Pilot Study on Secondhand Smoke Exposure in Homes

Transcription

1 Pilot Study on Secondhand Smoke Exposure in Homes Amy Van Deusen Mark Travers Andrew Hyland Terry Alford K. Michael Cummings Department of Health Behavior Roswell Park Cancer Institute

2 Table of Contents Acknowledgements 3 Executive Summary...4 Background and Introduction..5 Methodology.15 Results...20 Discussion.28 Conclusions...34 Appendix A: Real-time data plots..35 Appendix B: Log Sheet 49 References.50 2

3 Acknowledgements This report was prepared by the Department of Health Behavior, Division of Cancer Prevention and Population Sciences at Roswell Park Cancer Institute. The data collection protocols for the studies described in this report were developed at Roswell Park and approved by their Institutional Review Board. Funding for this project was provided by a grant to the Erie-Niagara Tobacco-Free Coalition from the New York State Department of Health, and by the Flight Attendant Medical Research Institute. The suggested citation for this report is as follows: Van Deusen A, Travers MJ, Hyland A, Alford T, Cummings KM. Pilot Study on Secondhand Smoke Exposure in Homes in Western New York. Buffalo, New York: Roswell Park Cancer Institute, Buffalo; December Requests for additional information concerning this survey should be directed to: Andrew Hyland, PhD Associate Member, Department of Health Behavior Division of Cancer Prevention and Population Sciences Roswell Park Cancer Institute Elm and Carlton Streets Buffalo, New York Phone: Fax: Andrew.Hyland@roswellpark.org. 3

4 Executive Summary Indoor air quality was assessed in 10 smoking homes and 3 smoke-free homes in Erie and Niagara Counties, between February 4, 2006 and August 24, Secondhand smoke exposure was estimated by measuring the concentration of particulate matter smaller than 2.5 microns in diameter (PM 2.5 ) using the TSI SidePak AM510 Personal Aerosol Monitor. Particles of this size are small enough to be inhaled deep into the lungs and are released in significant amounts from burning cigarettes or other forms of burning tobacco projects, and are responsible for a multitude of adverse health effects including cardiovascular and respiratory illness, pre-term delivery, childhood developmental defects, increased risk of SIDS, ear infections, asthma, stunted lung growth, and cancer. Home sites assessed included 3 smoke-free homes, in which smoking was prohibited, and 10 smoking homes, in which at least 5 cigarettes were typically smoked in the home each day. Our assessments encompassed 438 cigarettes and 715 hours among smoking homes and 220 hours among smoke-free homes. Key findings of the study include: Little difference was observed in the average PM 2.5 levels for the primary smoking and distal areas among smoking homes (84 micrograms per cubic meter and 67 micrograms per cubic meter, respectively, both in the unhealthy range based on EPA outdoor air standards). The average PM 2.5 level among smoke-free homes was 9 micrograms per cubic meter, which is in the healthy range based on EPA outdoor standards and all of these smoke-free homes (3 of 3) had fine particle exposures below EPA exposure limits. The average PM 2.5 level in smoking areas was 9-fold higher than that in smoke-free homes. Homes in which smoking occurs are significantly more polluted than smoke-free homes, and PM 2.5 concentrations reach unhealthy levels according to EPA standards for outdoor air. This study demonstrates that residents and visitors to smoking homes are exposed to harmful levels of secondhand smoke, a known human carcinogen. The ideal remedy is for smokers to quit, but until then, implementation of a smoke-free home policy can protect household members from unhealthy levels of pollutants from secondhand smoke. 4

5 Background and Introduction Health Effects Secondhand smoke is a mixture of the smoke given off by burning tobacco products and that exhaled from the smoker s lungs. The harmful effects of secondhand smoke (SHS), including death and disease, have been clearly established. According to the Surgeon General s 2006 report, healthy adult non-smokers exposed to secondhand smoke are at increased risk for heart disease and lung cancer and children exposed have a higher risk of SIDS, acute respiratory infections, ear problems, more severe asthma and slowed lung growth. 1, 2 Secondhand smoke is a known human carcinogen, as classified by the U.S. Environmental Protection Agency (EPA) and The U.S. National Toxicology Program. 3, 4 Earlier this year, California s Office of Environmental Health Hazard Assessment (OEHHA) declared environmental tobacco smoke (secondhand smoke) to be a toxic air contaminant (TAC) that may cause children and infants to be particularly affected by illnesses, including developmental defects, pre-term delivery, and cancer. 5 The harmful effects of secondhand smoke (SHS) have been well documented in the literature. 6 Known carcinogens are present in tobacco smoke, and exposure to SHS increases individuals risks of morbidity and mortality from cardiovascular diseases, lung and other cancers, and respiratory diseases. Most particles emitted from cigarettes, cigars and pipes are respirable suspended particles (RSP) less than 2.5 microns (PM 2.5 ) in diameter that are easily inhaled deep into the lungs. These particles are emitted from combustible materials when burning and are therefore not unique to secondhand smoke; however, it is known that cigarette smoke is a major source of these particles. Previous studies have measured levels of particulate matter (PM) to 5

6 indirectly measure SHS exposure in public places and have shown that patrons of these public 14, 15 venues are exposed to large and harmful levels of tobacco smoke. Besides secondhand smoke, there are a number of other pollutants that are bad for people s health, and although there are currently no set standards for indoor air, the EPA has issued standards for the quality of outdoor air (shown in Table 1). 7 The table below describes the average annual level standards for PM 2.5 exposure that were set with the intention to protect the public s health. Table 1: EPA Standards for ambient air quality for particulate matter 7 Air Quality Index Levels of Health Concern Good Moderate Unhealthy for Sensitive Groups Unhealthy Very Unhealthy Hazardous PM 2.5 (µg/m 3 ) Meaning Air quality is considered satisfactory, and air pollution poses little or no risk. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution. Members of sensitive groups may experience health effects. The general public is not likely to be affected. Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects. Health alert: everyone may experience more serious health effects. Health warnings of emergency conditions. The entire population is more likely to be affected. Impact of Smoke-free Policies The Current Population Survey (CPS) data shows that in , only 46% of worksites were smoke-free, and by , that number rose to 70 percent. 8 Nationwide, respondents of the National Human Activity Pattern Survey (NHAPS) reported that the largest amount of time spent 6

7 exposed to secondhand smoke occurred in residential locations. 9 With the increasing normative trend of clean indoor air laws governing public air in public places such as bars and restaurants, the home is increasingly becoming the primary source of secondhand smoke exposure for U.S. residents. Measures of Secondhand Smoke Exposure Cotinine measurements Cotinine is a metabolite of nicotine and can be found in blood, urine or saliva and is used as a marker for secondhand smoke exposure. Detectable levels of cotinine revealed that about 43 percent of U.S. residents at least 4 years of age were exposed to secondhand smoke, according to the NHANES data. 10 The 2006 Surgeon General s report cites that in 2000, there were an estimated 126 million US residents aged 3 years and older that were exposed to secondhand smoke. The Census Bureau s Current Population Survey (CPS) found that the proportion of smoke-free homes was only 66 percent in , which still leaves 34 percent of U.S. homes unprotected from secondhand smoke., 11 NHIS data from 1994 reveals that regular smoking (>= 1 day per week) occurs in 35% of homes with children-- an estimated 11 million homes and 21 million children. 12 Matt, et. al. (2004) documented multiple pathways of infants SHS contamination and exposure by measuring nicotine in household dust, air and surfaces and urine cotinine levels. Despite some smokers efforts to smoke outside, their levels of contamination and exposure were still 5-7 times greater than non-smoker s households, and levels among smokers who smoked inside the home were 3-8 times higher than the outsidesmokers homes. 13 A limitation to using cotinine as a marker for secondhand smoke exposure is that one cannot tease out the contributions of multiple sources of exposure from the one cotinine 7

8 level measurement; in other words, if a person is exposed both at home and at work, there is no way of determining the extent to which each location contributed to the cotinine level. Additionally, if an individual is smoking or wearing a nicotine replacement therapy patch, those nicotine products also contribute to the cotinine level and contributions of those products cannot be teased out from that of secondhand smoke. Air (PM 2.5 levels) measurements There is some data on air quality in homes and how secondhand smoke distributes throughout the home. The study by Matt, et. al. cited above looked at household dust, air nicotine, surface nicotine and hair and urine cotinine to assess infant exposure, but did not measure respirable particles. A field study in New York State (NYS) conducted in 1986 assessed vapor-phase nicotine and respirable suspended particles (PM 2.5 ) in 96 private homes. Cigarette consumption was recorded by the residents; however, time and place of smoking incidences was not recorded. Average PM 2.5 levels for households in which nicotine was detected (smoking households) were three times greater in homes where nicotine was detected (44 μg/m 3 ) than in homes without detectable nicotine levels (15 μg/m 3 ). Wallace (1996) reviewed studies that measured RSP concentration in homes in and found that on average, RSP concentration (PM 3.5 ) in smoking homes ranged from μg/m 3 above that in non-smoking homes. 19 These studies had only one average estimate of air pollution per home, did not assess variable levels of exposure in different areas of the home, and did not explore how the smoke distributes. Anecdotally, many smokers institute their own home-rule smoking policies and smoke in segregated areas of the home, with the belief that such policies offer protective factors under the 8

9 assumption that the smoke distributes in a certain way in their home. This commonly held belief was a major motivating factor for this study. Impact of Smoke-free Policy Interventions Previous studies have measured levels of particulate matter (PM) to indirectly measure SHS exposure in public places. Data from these studies have shown that patrons of these public venues are exposed to large and harmful levels of tobacco smoke. 14, 15 A pre-post longitudinal follow up of 24 hospitality workers in New York assessed self-reported secondhand smoke exposure and saliva cotinine levels before and after the state implemented a clean indoor air law. The average length of secondhand smoke exposure before the law was 12.1 hours, which decreased to 0.2 hours after the law. Self-reports were confirmed by saliva samples which reflected a drop in cotinine levels from 3.6 ng/ml before the law to 0.8 ng/ml after the law. 16 In a Delaware study, particulate matter and polycyclic aromatic hydrocarbons were assessed in public venues including a casino, bar/restaurants and a pool hall, before and after an indoor smoking ban went into effect. Before the smoking ban, the respirable particle levels averaged 20 times greater than outdoor levels. In contrast, post-ban, all but one venue had particulate matter levels comparable to outdoor air. The 24-hour average polycyclic aromatic hydrocarbon (PAH) levels before the smoking ban were about 3 times higher than background levels in the pre-smoking ban venues and the short-term work shift exposures were 5 times greater than post-ban levels. To bring these levels of respirable particles and PAH into perspective, pre-smoking ban, all venues had levels exceeding those measured on a heavy truck route during rush hours on a major interstate highway. 17 9

10 There was one study in public venues that looked at no smoking areas adjacent to regular use areas in licensed social and gaming clubs in Sydney, Australia. This study measured PM 10 levels simultaneously in the two areas and found that PM 10 levels were lower in the no smoking areas than in the general use areas, but were still much higher than ambient levels. PM 10 levels were 460 μg/m 3 and 210 μg/m 3 for regular use and no smoking areas respectively, compared to outdoor levels of 61 μg/m 3. The study concludes that no smoking areas offer little to no benefit in the context of this public venue does the same apply to homes? Our study aimed to address this question. Exposure assessment literature is summarized in Table 2. 10

11 Table 2. Literature table for SHS Exposure Studies Author, Title, Journal, Year Pub Focus Design (n-size) Matt GE, Quintana PJE, Multiple Quasiexperiment Hovell, MF, Bernert JT, exposures to Song S, Novianti N, secondhand comparing three Juarez T, Floro J, smoke groups of Gehrman C, Garcia M, mothers and their Larson S. infants Households (n=49) contaminated by environmental tobacco smoke: sources of infant exposures. Tobacco Control; Leaderer BP, Hammond SK. Evaluation of vaporphase nicotine and respirable suspended particle mass as markers for environmental tobacco smoke. Environ, Sci. Technol, Wallace, L. Indoor Particles: A Review. Journal of the Air & Waste Management Association, Field study measured RSP (PM 3.5 μg/m 3 ) and vapor-phase nicotine in 96 homes Review of secondhand smoke exposure and relevant studies - Measured RSP and Nicotine in 96 NYS homes with detectable levels of nicotine for 1 week - Cigarette or other tobacco consumption gathered from a diary kept by the residents - Summary article of various RSP studies Setting (Location) Homes (San Diego, CA) - Homes (New York State) in Private homes Participant or Setting Characteristic s/ Groups Compared -Smoking mothers who smoke in the home - Smoking mothers who smoke outside the home - Non-smoking mothers - Mothers infants - Private homes Exposure indicator, Outcome Measure (measurement device) -Household dust (area floor dust samples) -air nicotine (passive diffusion monitor badges) -surface nicotine (wipe sample) -cotinine (hair and urine) - RSP (PM 2.5 ug/m 3 ) - vapor-phase nicotine Key findings/ Comments - Exposure levels 3-8 times greater in homes where mothers smoke inside compared to homes were mothers smoke outside - Exposure levels 5-7 times greater in homes where mothers smoke outside compared to non-smoking homes - SHS contamination found in dust, surface areas and skin of the mother - RSP (PM 2.5 μg/m 3 ) among homes with detectable nicotine levels averaged 44 μg/m 3 - RSP (PM 2.5 μg/m 3 ) among homes without detectable nicotine levels averaged 15 μg/m 3 - The difference was 3-fold between homes with and without detectable nicotine levels - Did not control for location of cigarette smoking -Private homes - RSP (PM 3.5 μg/m 3 ) - Average RSP concentration in smoking homes was μg/m 3 above that in non-smoking homes. 11

12 Cains T, Cannata S, Roulos R, Ferson MJ, Stewart BW. Designated no smoking areas provide from partial to no protection from environmental tobacco smoke Tobacco Control, Invernizzi G, Ruprecht A, Mazza R, Rossetti E, Sasco A, Nardini S, Boffi R. Particulate matter from tobacco versus diesel car exhaust: an educational perspective Tobacco Control, Roswell Park Cancer Institute, International Agency for Research on Cancer, Harvard School of Public Health. A 20- Country Comparison of Levels of Indoor Air Pollution in Different Workplaces. (Report) June Effectiveness of designated no smoking areas Particulate matter pollution for cigarettes and ecodiesel engine Particulate matter pollution in public venues with and without smoke-free policies Descriptive study compared exposures in regular use areas to no smoking areas in licensed gaming clubs (n=17) Descriptive study compared PM levels of cigarettes to PM levels of an ecodiesel engine (n=3 replications) Descriptive studies compared PM 2.5 levels in smoking and smoke-free public venues (n=1132 overall, 227 in the US) Licensed [to sell alcohol] social and gaming clubs (Sydney, Australia) 60m 3 garage (an area in Italy with low outdoor PM levels) Public venues such as restaurants, bars, taverns, pubs (20 Countries) - Licensed social and gaming clubs - regular use area - no smoking area - outdoor air - In garage: 3 smoldering cigarettes (lit consecutively over 30 minutes - ecodiesel engine (idling for 30 minutes) - Smoking venues - Smoke-free venues - Atmospheric nicotine (passive sampler) - Particulate matter PM 10 (TSI Dustrack aerosol monitor) - PM 10, PM 2.5, PM 1 (laser operated aerosol mass analyzer) -PM 2.5 (TSI Sidepak AM510 Personal Aerosol Monitor) - Nicotine and PM 10 levels were lower in the no smoking areas than in the general use areas, but still much higher than ambient levels - Nicotine levels were μg/m 3 and 41.3 μg/m 3 in general and no smoking areas, respectively - PM 10 levels were 460 μg/m 3 and 210 μg/m 3 for smoking and no smoking areas, compared to outdoor levels of 61 μg/m 3 - PM levels from the cigarettes were 10 times greater than levels from the ecodiesel engine and 15 times higher than outdoor air - Note: The instruments were re-calibrated for secondhand smoke according to current standards in Italy - 1 hour into the study, PM 2.5 levels were 31 μg/m 3 for the engine and 319 μg/m 3 for the cigarettes - PM decay was very slow for the cigarettes and exceeded outdoor levels for an hour and a half after they were lit - Among all countries, the average PM 2.5 level in smoking venues was 321 μg/m 3 and in smoke-free venues it was 37 μg/m 3. - In the U.S., the average PM 2.5 level in smoking venues was 265 μg/m 3 compared to smoke-free venues which was 22 μg/m 3. 12

13 Travers MJ, Cummings KM, Hyland A, Repace J, Babb S, Pechacek T, Caraballo R. Indoor Air Quality in Hospitality Venues Before and After Implementation of a Clean Indoor Air Law Western New York, MMWR, November 12, Farrelly MC, Nonnemaker JM, Chou R, Hyland A, Peterson KK, Bauer UE. Changes in hospitality workers exposure to secondhand smoke following the implementation of New York s smoke-free law. Tobacco Control, Repace J. Respirable particles and carcinogens in the air of Delaware hospitality venues before and after a smoking ban. J Occup Environ Med Particulate matter pollution before and after implementat ion of a clean indoor air law Hospitality workers exposure to secondhand smoke before and after implementat ion of a clean indoor air law SHS and PPAH pollution in public venues before and after the smoking ban Pre-post longitudinal follow up compared PM 2.5 levels in public venues before and after a clean indoor air act went into effect (n=22) Pre-post longitudinal follow up (12- mo.) telephone survey and saliva cotinine analysis compared hospitality workers exposure to SHS before and after a clean indoor air law implementation (n=24) Pre-post longitudinal follow up Compared PM and PPAH levels before and after the smoking ban (n=8) Public venues such as bars and restaurants Hospitality workers working in restaurants, bars and bowling facilities Public venues including a casino, barrestaurants and a pool hall - Public venues before the clean indoor air law - Public venues after the clean indoor air law - Hospitality workers before the clean indoor air law - Hospitality workers after the clean indoor air law - Public venues before the smoking ban - Public venues after the smoking ban -PM 2.5 (TSI Sidepak AM510 Personal Aerosol Monitor) - Self-reported SHS exposure (telephone interview) - Saliva cotinine (saliva sample) - PM 3.5 (active-mode MIE PersonalData- RAM) -Particulate polycyclic aromatic hydrocarbons (EcoChem PAS 2000CE) - Among all venues which had smoking or SHS exposure at baseline, the average PM 2.5 level before the law went into effect was 328 μg/m 3 and 25 μg/m 3 after the law went into effect (decrease of 84%) - Average length of SHS exposure before the law was 12.1 hrs and decreased to.02 hrs after the law - Average saliva cotinine concentration before the law was 3.6 ng/ml and decreased to 0.8 ng/ml after the law - 88% of hospitality workers reported sensory symptoms before the law and only 38% reported such after the law. - Before the smoking ban, the respirable particle levels averaged 20 times greater than outdoor levels - After the smoking ban, all venues but one had respirable particle levels comparable to that of outdoor air - 24-hour average PPAH levels before the smoking ban were about 3 times higher than background levels in the pre-smoking ban venues and the short-term work shift exposures were 5 times greater than post-ban levels - PPAH and RSP levels for all venues pre-smoking ban were higher than levels measured on a heavy truck route during rush hours on a major interstate highway 13

14 The gap this study fills The published literature has studied public venues more than private residences. The study that simultaneously measured adjacent smoking and non-smoking areas was the study by Cains, et. al. in Australian gaming clubs. The few home studies relied on self-report, which has accuracy limitations, and cotinine, which reflects a person s entire SHS exposure, not only exposure from a specific area. The NYS home study did assess the number of cigarettes smoked and RSP levels; however, the results were aggregated and times of the incident smoking activities were not directly matched with log data. 18 We designed our pilot study to fill the gap by objectively measuring SHS exposure in real-time, using PM 2.5 as a marker; and comparing two areas of the home the primary smoking area and a distal area, where smoking typically does not occur. A unique aspect of our study was our activity logs, which we could use to match the logged smoking activity of the occupants with the PM 2.5 readings in order to explain the PM 2.5 levels. Objectives The objectives of this study were 1.) To assess and compare levels of secondhand smoke in homes where smoking is permitted and smoke-free homes and 2.) Among smoking homes, to assess and compare levels of secondhand smoke in the primary smoking areas to those in the distal areas, where smoking typically does not occur, in order to explore how the smoke distributes throughout the home. 14

15 Methodology Summary of Methods In this pilot study, we measured the air quality in real time, over a 3 day period, in a crosssection of 10 smoking homes and 3 smoke-free homes, using the same air quality measurement procedures that have successfully been used in public venues. We obtained estimates of levels of SHS in two locations per smoking home, in order to examine how SHS is distributed throughout homes where smoking is allowed. The PM 2.5 levels among smoking homes were compared to those among the smoke-free homes. We hypothesized that within homes where smoking is permitted, the levels of pollution would be elevated throughout the home, rather than in isolated areas of the home, and considerably higher and unhealthier than those in smoke-free homes. Recruitment & Eligibility From February through August, 2006, 13 participants were recruited by word of mouth and flyer postings, including 10 smokers who smoke inside their home and 3 non-smokers who prohibit smoking in their home. A $50 incentive check was given to participants as a token of appreciation for participating in the study. Eligibility criteria for the smoking households required that the participant currently smoke at least 5 cigarettes per day in the home and agree to record a log of all smoking and other activities that could influence PM 2.5 levels throughout the air monitoring period. In order to sample a range of smoking activity, five of the smoking homes were required to report that on a typical day, 5-14 cigarettes are smoked in the home, and the other five were required to report 15 or more cigarettes. The smoke-free homes were required to prohibit smoking in their home. All 15

16 participants were required to be at least 18 years of age and to provide a written, informed consent at the time of the staff s first visit to the home. Methodology for air monitoring: Log Data A short questionnaire was administered to obtain in-home smoking activity history for the last 24 hours (smokers only), and baseline log data that accounted for any smoking activity, heating or cooling appliance activity, cooking activity, candle use and window placement (open/closed) was established. This log data was kept for the purpose of monitoring any factors that may affect the PM 2.5 level. The participant was trained on how to fill out the log sheet and was instructed to continue filling out the log sheet throughout the hour period of data collection. It was emphasized that the participant should note the time to the specific minute so that the log data could be accurately matched to the air monitoring data. PM 2.5 Data Source: Equipment TSI Sidepak AM510 Personal Aerosol Monitor For our air monitoring methodology, we used the TSI SidePak, a scientifically valid and effective tool for real time PM 2.5 monitoring in secondhand smoke studies. The Sidepak uses lightscattering technology to determine mass concentration in real-time. The internal sampling pump draws an aerosol in a continuous stream into the sensing chamber where it is illuminated by a small beam of laser light. Particles in the aerosol stream scatter the light and a photodetector 16

17 detects the amount of light scattered, which is in turn converted to the mass concentration of the aerosol. The mass concentration is proportional to the amount of light scattered. The Sidepak was set to measure PM 2.5 by fitting it with a 2.5 micron impactor. The flow rate was set at 1.7 liters per minute using a TSI Model 4146 Primary Calibrator to ensure proper operation of the impactor. Data collected from this device was used to calculate the levels of SHS in the home, as the SidePak readings linked with the log data can show an immediate, direct causal link between smoking and fine particle air pollution. The SidePak weighs less than one pound and is relatively quiet, sounding similar to white noise. When plugged in and turned on, it runs continuously. Calibration factor: A calibration factor of 0.32 was applied to the Sidepak readings, which is appropriate for secondhand smoke particles. This laser photometer works on a light-scattering principle, and since different particles scatter light in different ways, the device needs to be calibrated appropriately for the particles one wants to measure. 17 The factor of 0.32 was determined from calibration experiments with the ThermoMIE personal DataRAM model pdr-1200 real-time aerosol monitor (ThermoAndersen, Inc, Smyrna, GA, USA) which was calibrated against standard pump-and-filter gravimetric methods, considered the gold standard for particle mass concentration measurement. 15 This 0.32 calibration factor was also used in other studies using the Sidepak 15 and has since been verified by directly comparing the Sidepak to the pump-andfilter gravimetric by Kiyoung Lee, PhD, at the University of Kentucky (personal communication). 17

18 Location & set-up of monitors: Two sets of equipment were placed in each household. Among smoking households, the first set was placed in the room where smoking most often occurred and the second set was placed in a room most distal to the majority of smoking activity. Among non-smoking households, one set of equipment was set up in the kitchen area, potentially the most polluted room among nonsmokers homes due to cooking activities, therefore making our comparison of smoking to smoke-free homes conservative; the other set of equipment was set up in another room, where it would be out of the participant s way. Monitors were cleaned and zero-calibrated at the beginning of the monitoring period. The monitors were placed on tables, countertops and dressers so that measurements would be taken in the range of normal breathing levels. Participants were instructed not to touch the equipment and the keypads were locked to help ensure they were not tampered with. The logging interval was set to one minute, meaning the equipment logged the average concentration each minute so that the PM 2.5 levels could be matched to the participants log data on a specific level of detail. Duration of air monitoring: In each household, the two monitors ran continuously over a three day period, recording a new measurement every minute. It is important to note that the monitors were running continuously including overnight during periods of inactivity and sleep. Room dimension measurements: 18

19 The Zircon DM S40 Sonic Measure (Zircon Corporation, Campbell, CA) or the Strait-Line Sonic Laser Tape ( were used to measure the dimensions of the living area so that the volume of the living area could be calculated in cubic meters. Analysis: After sampling was finished, the air monitoring data was downloaded from the Sidepak and QTrak (This is the first mention of the QTrak) units onto the computer using TrakPro v3.41 software. Any data points for non-overlapping minutes between units were removed for analysis so that each logged minute was matched by the other air monitor. A calibration factor of 0.32 was applied to the Sidepak data, which is appropriate for secondhand smoke. Descriptive statistics on hours sampled, living space volume and number of cigarettes smoked were explored. The primary outcome measurement was the average concentration of PM 2.5 in micrograms per cubic meter. The average levels of PM 2.5 were computed among primary smoking areas, distal areas, and smoke-free homes by averaging the minute by minute levels over the timeframe of the study period. The PM 2.5 levels of the smoking room were compared to that of the distal rooms and to levels in the smoke-free homes as well as to outdoor air levels. For the average outdoor air PM 2.5 level, we used the EPA website s annual mean 24-hour value for Erie County, which was 11.5 micrograms per cubic meter. 22 One air monitor in the primary smoking area (ID#4) had invalid readings due to excessive humidity and that data has been excluded from analysis. The PM 2.5 levels were further broken down by number of cigarettes smoked (less than 15 cigarettes per day vs. 15 or more cigarettes per day) and housing type (efficiency apartments vs. non-efficiencies). The average smoking density of the smoking rooms 19

20 was calculated by dividing the number of cigarettes smoked over the study period by number of hours on the study, by 100 cubic meters of living space. The average smoking density was plotted against PM 2.5 levels. The correlations between the smoking and distal areas for the 9 smoking homes that had valid PM 2.5 data were explored. The distal room monitor s PM 2.5 data was lagged by each minute from 0 up to 30 minutes to determine which lag interval reflected the highest correlation between the smoking area monitor and the distal area monitor. Lastly, the log data from participants activity logs was used to match up with the minute-interval PM 2.5 data to explain fluctuations in PM 2.5 levels. Results Duration: The average time that the monitors ran in the home was 71.9 hrs (range, 65.9 hrs to 77.9 hrs). Among smoking homes, the average duration was 71.5 hrs (range, 65.9 hrs to 77.9 hrs) and among smoke free homes, the average duration was 73.3 hrs (range, 70.9 hrs to 77.5 hrs). Living space volume: The average room volume of the smoking room in the smoking households was 31.5 m 3 (range, 6.4 m m 3 ). The average room volume of the distal area of the smoking households was 30.8 m 3 (range, 17.7 m 3 to 62.7 m 3 ). Two of the households (ID#8 and ID#9) were efficiency apartments, so the smoking and distal areas were not clearly separated by a physical barrier and for these calculations the volume was measured as one area and used for both the primary smoking area and distal area calculations. The average total household volume was m 3 20

21 (range, 30.9 m 3 to m 3 ) for the smoking homes and m 3 (range, 83.2 m 3 to m 3 ) for the smoke free homes. Log Data: The participant recorded the number of cigarettes, any use of heating or cooling appliances, cooking activities, and window or door placement (open/closed) throughout the period of air monitoring. These data were compared to the real-time air monitoring data in order to explain the various levels of air pollution and interpret the graphs. Average PM 2.5 Concentrations: Figure 1 shows the average PM 2.5 concentrations among smoking areas, distal areas and smokefree homes and compares these to outdoor air. The average PM 2.5 concentration in the primary smoking areas of smoking households was 83.6 μg/m 3 (range, 22.6 μg/m 3 to μg/m 3, n=9), approximately 1.4 times (range, 1.0 to 2.0) greater than that for the distal rooms among smoking households and 9.8 times (range, 2.6 to 33.3) greater than that for the smoke free homes. The average PM 2.5 concentration for the distal room in smoking households was 67.4 µg/m 3 (range, 13.9 μg/m 3 to μg/m 3, n=10), 7.9 times (range, 1.6 to 22.7) greater than that for the smoke free homes. The non-smoking households PM 2.5 concentration overall was 8.6 μg/m 3 (range, 6.4 μg/m 3 to 12.4 μg/m 3, n=3). Smoking and distal area PM 2.5 levels were comparable and were not statistically different according to the Mann-Whitney U-test (p=0.720). Smoke-free homes had significantly lower 21

22 PM 2.5 levels than both smoking and distal areas of the smoking homes (p=0.009 for smoking areas vs. smoke-free homes; p=0.007 for distal area vs. smoke-free homes). Figure 1. PM 2.5 Comparisons among smoking and distal areas in smoking homes, smokefree homes, and outdoor air Smoking areas Distal areas 9 11 Smokefree homes Outdoor air* *Average outdoor PM 2.5 level for 2006 in Erie County as measured by the U.S. EPA Federal Reference Method, accessed on August 28, 2006 The average annual-to-date PM 2.5 concentration for outdoor air in Erie County, NY for 2006 was 11.5 μg/m 3 (accessed August 28, 2006). According to EPA standards, an individual s annual average concentration should not exceed 15.0 μg/m When stratifying by cigarettes per day (cpd) and type of housing (efficiency apartments vs. nonefficiencies), the PM 2.5 levels vary (as shown in Figure 2). Among the 5-14 cpd households, the average PM 2.5 concentration in the primary smoking rooms was 49.8 μg/m 3 (range, 22.6 to 92.0 μg/m 3, n=5), averaging 1.2 times (range, ) greater than that among the distal rooms, which 22

23 averaged 46.9 μg/m 3 (range, 13.9 to 95.8 μg/m 3, n=5) and 5.8 times (range, 2.6 to 10.8) greater than that for the smoke free homes. Two of the 5-15cpd homes were efficiency apartments. Looking at these separately, it is seen that the efficiency apartments have much higher levels of PM 2.5 than the non-efficiency homes. This can be explained in part by the average volume of the living spaces. Overall among the 5-14 cpd homes, the average volume was m 3 ; among efficiency apartments, the average was 39.9 m 3 and among non-efficiencies, the average size was m 3. The increased PM 2.5 level among efficiencies can also be explained by the smoking room densities. The overall average smoking room density among 5-14 cpd homes, as calculated by dividing the number of cigarettes smoked in the primary smoking area, divided by the hours sampled, per 100 cubic meters, was 0.80 cigarettes/hr/100m 3. Among the efficiencies, the average was 0.87 cigarettes/hr/100m 3 and among the non-efficiencies, the average was 0.75 cigarettes/hr/100m 3. Among the 15+ cpd households, the average PM 2.5 concentration in the primary smoking rooms was μg/m 3 (range, 26.8 to μg/m 3, n=4), averaging 1.6 times (range, 1.3 to 2.0) greater than that for the distal rooms, which averaged 88.0 μg/m 3 (range, 17.1 to μg/m 3, n=4) and 14.7 (range, 3.1 to 33.3) times greater than that among smoke free homes. 23

24 Figure 2. Average PM2.5 levels among household types PM2.5 level (ug/m3) Smoking areas Distal areas Smoke-free homes Overall 15+ cpd <15 cpd, overall <15 cpd, non-efficiency <15 cpd, efficiency apt. Cigarettes The average number of cigarettes smoked in the smoking areas of smoking households over the monitoring period was 33 (range, 13 to 62) cigarettes. The average of the total number of cigarettes smoked throughout the home was 44 (range, 13 to 92) cigarettes. Among the 5-14 cpd households, the averages for the primary smoking area were 19 cigarettes (range, 13 to 26) and for the total household space, 20 cigarettes (range, 13 to 26). Among the 15+ cpd households, the averages were 47 cigarettes (range, 20 to 62) smoked in the primary smoking area and 67 cigarettes (range, 36 to 92) for cigarettes smoked in the entire household. 24

25 Active smoking density (primary smoking areas): The average active smoking density for primary smoking areas among all smoking homes was 2.3 cigarettes/hour/100m 3 (range, 0.4 to 8.2 cigarettes/hour/100m 3, n=10). Among the 15+ cpd households, the density averaged 3.8 (range, 1.3 to 8.2 cigarettes/hour/100m 3 ) which averaged 4.7 (range, 3.0 to 6.2) times greater than that for the 5-14cpd households, which had an average density of 0.8 cigarettes/hour/m 3 (range, 0.4 to 1.3 cigarettes/hour/100m 3, n=5). Generally, as the active smoking density of the smoking area increases, the average PM 2.5 level of that area also increases (see Figure 3). The correlation coefficient is (p=0.421). Different ventilation rates may contribute to the strength of the correlation. Figure 3: Average smoking density of the smoking area plotted against PM 2.5 level of the smoking area, among smoking homes (n=9)*. 300 PM2.5 level (ug/m3) *r = 0.307, p= Smoker Density (cig/hr/100m3) 25

26 Correlations Figure 4: Number of minutes lagged between smoking and distal monitors to achieve the highest correlation r = minutes r = minutes 5 0 r = minutes low medium high Barrier strength Low: efficiency apartments with no physical barriers or 20 between air monitors Medium: 30 between monitors High: Over 30 between monitors When the distal room monitor s PM 2.5 data was lagged by each minute from 0 up to 30 minutes to determine which lag interval reflected the highest correlation, not surprisingly, we found that homes where the monitors were closest together had the lowest lag time, and homes with the greatest distance or barrier between them had the longest lag time, as shown in Figure 4. Additionally, the correlations were highest among those homes with the lowest barrier between the monitors. Those with the lowest barrier strength were the efficiency apartments and a small apartment without a closed door separation, in which the monitors were only about 20 feet apart. This is consistent with Ott and Klepeis s experimental finding that two adjacent rooms with little separation, for example, no closed door between them, behave like a single compartment and therefore, there is little difference between the PM 2.5 levels of the two. 23 Homes with the highest barrier strength were those in which the monitors were over 30 feet apart; those with medium 26

27 barrier strength were in the middle. In other words, it takes about 30 minutes for peak levels of secondhand smoke to drift to distal areas of larger spaces, where as exposure in places closer to the source occurs more rapidly. The bottom line is that the smoke still gets to distal areas it just takes longer for it to get there when the living area is larger or if there are more barriers in the pathway. This study provides real-world data that can be used to validate modeling techniques. Real-time plots: Real-time plots of the PM 2.5 levels were graphed over time for each household. The real-time plots for each household are shown at the end of this report in Appendix A. For each household, the blue graph line shows the PM 2.5 levels of the smoking area and the yellow graph line shows that of the distal area. Footprints of each household are sketched on the bottom right-hand corner of each plot to give the reader a sense of the layout of the household; these footprints are not drawn to scale. Time points of smoking event incidences, as taken from the participant log data, are labeled across the top of each graph. As demonstrated in ID#01 s graph, the spikes of PM 2.5 are explained by the instances of smoking. The peak PM 2.5 reading was approximately 400 μg/m 3 in the first day of monitoring, during the time when 10 cigarettes were smoked. The decay back to baseline occurs after the smoking ceased (in this case, the participant went to bed after smoking the 10 cigarettes). Upon waking the next day, the participant smoked 3 cigarettes, which caused another spike in PM 2.5, before going out of the home for the day, and the decay back to baseline is visible when there was no smoking activity logged. Upon returning home, the participant smoked 4 cigarettes, once again elevating the PM 2.5 levels, and so on. This direct link between logged smoking activity and rise in PM 2.5 levels was observed across all of the smoking 27

28 homes. This household was relatively small in total living space volume and one can see that there is practically no lag time between the times when the smoke from the cigarettes smoked in the primary smoking area causes an elevation in the distal area as well. In contrast, ID#13 has a longer lag time between the elevation of PM 2.5 levels between the times that cigarettes are smoked in the primary smoking area, which is on the first floor, and when the smoke causes the elevation in PM 2.5 level in the distal area, which is upstairs on the second floor. Discussion The results of the air monitoring data for each household, 10 smoking and 3 non-smoking households, are shown in Table 3 and are summarized by cigarettes per day and housing type categories in table 4. The average PM 2.5 level of smoking rooms in smoking households was 83.6 μg/m 3, a harmful level according to EPA standards for outdoor air, 9.8 times greater than the non-smoking households and 5.6 times greater than the EPA s recommended annual mean average of 15 μg/m 3. Additionally, the PM 2.5 level average of distal areas among smoking homes was 67.4 μg/m 3, similarly an unhealthy level, and 7.9 times greater than that of nonsmoking households and 4.5 times greater than the EPA standard noted above. In other words, there was no difference in pollution levels regardless of whether the measurements were taken in the room where most of the smoking was going on or a distal area with no smoking occurring; however, these levels were much higher than what was observed in the smoke-free homes. The PM 2.5 levels found in this study are higher than those found in previous home studies 18,19 and lower but still comparable to levels found in other studies that have assessed the air quality of smoky bars and restaurants that used the same equipment and air sampling procedure. A key 28

29 difference between this study and studies done in public venues is that this study averages PM 2.5 levels across entire days, including evenings when participants are sleeping and there is no active smoking activity. This feature of our study makes our measurements more representative of typical secondhand smoke exposure since we encompass these hours of the day. Additionally, it is easier to compare our results to the EPA recommendations for 24-hour or annual mean exposure levels since our study encompasses a wider range of time points. Additionally, this study supports the findings of a study that concurrently measured PM 10 levels in a hospitality venue s smoking and non-smoking designated areas and concluded that the no smoking areas did not offer protection from the smoking activities going on in adjacent areas. 24 The log data reflect various actions that would be thought to have an effect on the ventilation of the secondhand smoke. Windows were placed in the open position, fans were running, and in one case an air purifier was used. The PM 2.5 levels still reached unhealthy levels despite any changes in ventilation or circulation of the air. Ventilation nor separation by space is not a solution and should not be used as a measure to protect people from the harmful effects of secondhand smoke. Peak levels occurring during heavy smoking periods have reached over 1,000 μg/m 3 (ID#03), which is comparable to what has been found in some of the most polluted public venues, such as a pool hall before the implementation of a smoking ban. 14 Referring back to the EPA standards, levels of this magnitude exceed the highest hazardous level on the EPA chart for average annual exposure standards. 29

30 Table 3. Descriptive summary statistics for smoking and smoke-free homes Smoking area, average PM 2.5 (μg/m 3 ) Distal area, average PM 2.5 (μg/m 3 ) ID No. Smoking status Housing type Hours Size (m 3 ) Total # cigarettes Avg. smoker density* 5-14 cpd non-efficiencies cpd 1-floor apartment cpd 1-floor house cpd 2-floor house Mean cpd efficiencies cpd Efficiency apartment cpd Efficiency apartment Mean Mean cpd homes cpd 1-floor house cpd 2-floor Invalid house cpd 1-floor apartment cpd 2-floor house cpd 1-floor apartment Mean Smoking Mean** Smoke-free homes 2 None 1-floor apartment N/A None 1-floor N/A 12.4 apartment 11 None 1-floor house N/A 6.9 Smoke-free Mean^ N/A 8.6 * Average smoking density for the smoking area calculated by dividing the number of cigarettes smoked in the smoking room by the hours of sampling time divided by the smoking area s volume in 100m 3 to give a measure of cigarettes/hr/100m 3 Mean of the values for the 5-14cpd non-efficiency homes and 5-14cpd efficiency homes categories Mean of the values for homes in all 5-14 cpd and all 15+ cpd categories ** Mean for all smoking homes For smoke-free homes, this reflects the average of the 2 air monitors ^ Mean for all smoke-free homes 30

31 Table 4. Average PM 2.5 levels by cigarettes per day and housing type categories Smoking area, Smoking Category Sample size Hours Average size (m3) Average number of cigarettes Avg. smoker density* average PM 2.5 (μg/m 3 ) Distal area, average PM 2.5 (μg/m 3 ) 5-14 cpd nonefficiencies cpd efficiencies All 5-14 cpd All 15+ cpd All Smoking** Smoke-free^ * Average smoking density for the smoking area calculated by dividing the number of cigarettes smoked in the smoking room by the hours of sampling time divided by the smoking area s volume in 100m 3 to give a measure of cigarettes/hr/100m 3 Mean of the values for the 5-14cpd non-efficiency homes and 5-14cpd efficiency homes categories Mean of the values for homes in all 5-14 cpd and all 15+ cpd categories ** Mean for all smoking homes For smoke-free homes, this reflects the average of the 2 air monitors ^ Mean for all smoke-free homes Figure 5 depicts the almost 8-fold increase in distal areas and 10-fold increase in primary smoking areas, over smoke-free homes. Figure 5. PM 2.5 levels 100% increases for smoking homes relative to smoke-free homes smoking areas distal areas smoke-free homes 31

32 The average PM 2.5 level among smoking areas was almost 10 times higher than that in smoke-free homes. The average PM 2.5 level among the distal areas was almost 8 times higher than that in smoke-free homes. The average PM 2.5 level among smoking areas was only 24% greater than that in distal areas, showing no protection. The study done in New York State (NYS) homes 20 years ago is the study with a design most comparable to our study. Like theirs, our study reflected PM 2.5 levels in the healthy range according to EPA standards for outdoor air, among smoke-free homes. However, our study showed an 8 to 10 fold increase in PM 2.5 level among smoking homes compared to smoke-free homes, as opposed to their 3-fold increase. The NYS study One possible explanation for this finding is that the NYS study did not take into account monitor placement specifically in reference to primary or distal smoking areas (they were placed 2-3 m from the combustion source which could include gas stoves, kerosene heaters, wood-burning stoves, for example), so our monitors could be picking up levels in characteristically different locations. Additionally, their sample size of 96 is significantly larger than ours, and they sampled over a week, whereas we only sampled for 3 days. One possible explanation is that our homes tended to be smaller in size, with an average volume of only 155 m 3 since we included apartments and efficiency units. The NYS study only included detached single family homes with an average volume of 353 m The average number of cigarettes smoked per day in our study was 11.2 cigarettes, which is comparable to that in the NYS study, 10.2 cigarettes. Additionally, ventilation characteristics from our study to their may not be comparable, especially due to the smaller volume of homes in our study. 32

33 Limitations PM 2.5 is not specific to SHS and particles of this size are emitted as a form of combustion. Candle burning, cooking, heating or cooling appliances may also affect pollution levels; however, since we had participants log these activities as well, we could monitor for these activities and from our log to real-time plot comparisons, we confidently conclude that the spikes of unhealthy PM 2.5 levels are a result of active smoking. An examination of the log data indicated that other contributors to PM 2.5 such as cooking sometimes yielded small short-term changes in PM 2.5 ; however, compared to the wide fluctuations observed when smoking was occurring, the presence of these other sources was relatively insignificant. Although the log data across subjects was fairly accurate, log data was not always kept to the exact minute and subjects reported that they experienced difficulty trying to log others smoking behavior, specifically if the subject was not home during the time. As a result, there are some spikes in PM 2.5 levels in the real-time data plots that are not explained by the log data; however, since there were few occasions of this and judging from the rest of the matching log-to-real plot data, it is reasonable to infer that active smoking was going on at these time points. One participant s log record reflects that marijuana pipe smoke went on during the monitoring period. Although this study was intended to describe the effects of cigarette smoke, the PM 2.5 levels are clearly also affected by the marijuana smoke and reach unhealthy levels. Two participants had efficiency apartments and therefore the space between the active smoking area and distal monitors did not have a significant physical barrier. Overall, our homes had relatively small living space volumes, and only half of our homes were single-unit houses. At 33

34 this point, the point to which we can generalize our results is unclear; however, Figure 2 demonstrates that PM 2.5 levels depend on the number of cigarettes smoked and the volume of the living area in which they are smoked, and all instances showed that the air is dirtier in smoking homes than in non-smoking homes. Implications This study clearly demonstrates that among 10 smoking households, with various living area volumes and various numbers of cigarettes smoked per day, all of the scenarios under which smoking occurs in the home created unhealthy air. Anyone residing in the households in which there is active smoking is therefore exposed to unhealthy levels that have undesirable health consequences. The ideal solution to protect everyone living in the home is for the smokers to quit and for the occupants to institute a smoke free home policy. Until the smokers quit or if the smokers are not willing to quit, instituting the smoke free home policy will still protect others in the home from harmful secondhand smoke in their personal living space. Conclusions This pilot study demonstrates that secondhand smoke pollution in homes reaches unhealthy levels, according to EPA guidelines for outdoor air. Efforts to reduce the levels of air pollution, such as opening windows or using fans, do not prevent the air in other areas of the home from becoming polluted. Contrary to what occupants may believe, smoking in one area or room of the home does not protect the distal areas from secondhand smoke exposure. The smoke disperses throughout the home environment, and levels are similar or only reduced in other areas of the home and are still at harmful levels. The ideal solution to protect those occupants in smoking 34

35 homes is for the smokers to quit. Until the smokers quit, one way to protect others breathing the air inside the home is to prohibit smoking in the home. 35

36 Appendix A: Real-time data plots ID#01, Smoking home distal area smoking area , smoking 1, distal 3, smoking 4, smoking 1, smoking 2, smoking 1, other PM 2.5 level (µg/m 3 ) Hours elapsed: 76 Total cigarettes: 22 Total space volume: 126m 3 Housing type: 1-floor apartment Avg. smoking room density: 0.6 cig/hr/100m 3 Smoking area average (min, max): 39 (1, 371) µg/m3 Distal area average (min, max): 38 (1, 402) µg/m3 36

37 ID#02, Smoke-free home other room kitchen PM 2.5 level (µg/m 3 ) Lysol sprayed in kitchen 10 0 Hours elapsed: 71 Total volume: 83m3 Housing type: 1-floor apartment Overall average PM2.5 (min, max): 6 µg/m3 (2, 78) µg/m3 kitchen other 37

38 ID#03, Smoking home distal area smoking area , smoking 17, smoking, 1 other 7, smoking 18, smoking 10, smoking 1600 PM 2.5 level (µg/m 3 ) Hours elapsed: 66 Total no. cigarettes: 63 Total volume: 156m 3 Housing type: 1-floor house Avg. smoking room density: 2.2 cig/hr/100m 3 Smoking area average (min, max): 285 (5, 1537) µg/m3 Distal area average (min, max): 194 (6, 984) µg/m3 38

39 ID#04, Smoking home distal area *1 *7 + chain PM 2.5 level (µg/m 3 ) Other, upstairs * Other, same fl. + Smkg, same fl Hours elapsed: 74 Total no. cigarettes: 36 Total volume: 156m3 Cpd category: 15+ Housing type: 2-floor house Avg. smoking room density: 4.2 cig/hr/100m3 Distal area average (min, max): 110 (1, 677) µg/m3 first floor second floor 39

40 4 smk 1 smk 26 smk, 1 oth ID#05, Smoking home distal area 1 smk, 1 oth 19 smk, 3 oth smoking area 1 smk, 1 oth 4 smk, 1 oth PM 2.5 level (µg/m 3 ) Hours elapsed: 66 Total no. cigarettes: 63 Total volume: 85m3 Cpd category: 15+ Housing type: 1-floor apartment Avg. smoking room density: 8.2 cig/hr/100m3 Smoking area average (min, max): 117 (1, 1646) µg/m3 Distal area average (min, max): 60 (4, 281) µg/m3 40

41 ID#06, Smoke-free home other room kitchen PM2.5 level (µg/m3) Toaster oven, kitchen Oven & electric stove, kitchen Electric stove, Vacuum, other room kitchen other Hours elapsed: 72 Total volume:186m3 Housing type: 1-bedroom loft-style apartment Overall average PM 2.5 (min, max): 12 (3, 37) µg/m 3 kitchen 41

42 c= cigarette p= pipe/marijuana PM 2.5 level (µg/m 3 ) c* 1c* ID#07, Smoking home 1c+ 2c+ 2c+ 6c. 3p+ 2c+ 1c+ 1c+ 9c, 2p-- 5c, 2p-- 1p, 1c, 1c-- *other, upstairs Hours elapsed: 71 + other, same floor Total no. cigarettes: smoking area Total volume: 237m 3 Cpd category: 15+ Housing type: 2-floor home Avg. smkg. rm. density: 2.9 cig/hr/100m 3 distal area 1p, 2c+ 3c+ 8c, 4p-- 10c, 5p-- 74 (3,895)ug/m 3 59(3,327)ug/m 3 first floor smoking area 1c+ 3c+ 4c, 1p-- 2c, 2p-- second floor 42