Source apportionment of polycyclic aromatic hydrocarbons (PAHs) and carcinogenic risk estimate in Taranto, Italy

Transcription

1 Source apportionment of polycyclic aromatic hydrocarbons (PAHs) and carcinogenic risk estimate in Taranto, Italy M. Serinelli, C. Calculli, I. Galise, L. Bisceglia, A. Pollice, G. Assennato MARIA SERINELLI

2 BACKGROUND Polycyclic aromatic hydrocarbons (PAHs) are formed during incomplete combustion or pyrolysis of organic material and in connection with the worldwide use of oil, gas, coal and wood in energy production. PAHs are ubiquitous in the occupational and general environment. It has long been known that several PAHs can produce cancers in experimental animals and epidemiological studies of exposed workers, especially in coke ovens and aluminum smelters, have shown clear excess of lung cancer and highly suggestive excesses of bladder cancer (Quoted in Natl. Cancer Inst. Monogr. 1963,10:7, Mastrangelo et al., 1996, Environ. Health Perspect. 104: , Armostrong et al. 2004).

3 BACKGROUND Cancer risk assessment of individual PAHs are based mainly on tests in laboratory animals and occupational epidemiological studies. For several reasons, risk estimation of PAH exposures is a complex issue: - Although the existence of cancer risk is beyond reasonable doubt, considerable uncertainty exists as to the exposure-response relationship, and hence as to the risks posed at today s levels in the workplace and general environment. Information on this relationship is clearly important for setting of occupational and environmental standards. - PAHs comprise a mixture, several components of which are carcinogens

4 BACKGROUND The best-known PAH is benzo(a)pyrene (BaP) and the abundance of information on toxicity and occurrence of PAHs is related to this compound. BaP is frequently used as an index of PAH exposure, because it, as well as being an important carcinogen itself, is usually quite correlated with the other known carcinogens in the PAH mixture. The International Agency for Research on Cancer (IARC) considers BaP carcinogenic to humans (Group 1). Examples: EPA, IARC Cancer Monographs Target value of BaP annual mean: 1ng/m 3

5 INTRODUCTION In 1989 the town was officially defined as an Area at high environmental risk and later it was included in the 17 Sites of National Interest that need to clean up. This is due to the massive presence of industrial sites with high environmental impacting activities, including one of the largest iron production plants in Europe, oil-refinery, cement production and many more.

6 INTRODUCTION Figure 1 - Malignant neoplasm of trachea, bronchus and lung: males ( ) Significant Non significant LOS VAL BORMIDA PO POLESINE PO di VOLANO CONOIDI MASSA MANFREDONIA NAPOLI SARNO TARANTO BRINDISI PORTOSCUSO CROTONE AUGUSTA GELA SMR Figure 2 - Risk Map of lung cancer Taranto Table 1 - Standardized Incidence Rate for some cancers, Males Causes of disease Taranto Area at high environment risk Taranto Province Rate CI 95% Rate CI 95% Rate CI 95% All cancers Trachea, bronchus and Lung Pleura Bladder Non Hodgkin s Lynphoma Soft Tissues

7 OBJECTIVE In 2009 the reference value of BaP in ambient air of 1ng/m 3 has been exceeded in the urban district of Taranto surrounding the industrial area. Aim of the study: - to identify emission sources and quantify their relative contribution to PAHs levels in the urban district of Taranto; - to estimate health impact associated to PAHs exposure in general population.

8 ENVIRONMENTAL DATA Figure 3- Dislocation of selected monitoring station of Figure 4 - Monthly average concentrations of BaP (ng/m3) measured at 3 locations in Taranto. B[a]P in Taranto May December 2009 Alto Adige Talsano Table 2- BaP levels (ng/m3) in Taranto Via Machiavelli Via Alto Adige Talsano 1.31* *Target value of B(a)P annual mean value: 1ng/m3 Machiavelli

9 ENVIRONMENTAL DATA PAHs Analyse in continuum Total PAH average levels with wind speed < 0.5 m/s Total PAH average levels with wind speed > 0.5 m/s Sectors Figure 5 - Total PAH average levels (ng/m3) in dependence of wind direction. N NNW NW WNW W NNE NE ENE E WSW ESE SW SE SSW SSE S N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Total PAHs average levels (ng/m3)

10 ENVIRONMENTAL DATA Table 3. Total PAHs and BaP levels in the sampling campaign carried out with wind select device Sample sites Sectors Period Taranto - Lago di Bolsena Street (compared with industrial area) Taranto - Tamburi Church (compared with industrial area) Taranto - Tecnomec Statte - Carmine farm Total PAH* (ng/m 3 ) Benzo(a)pyrene (ng/m 3 ) WIND, DIRECTLY FROM THE SOURCE 2008/08/ ALL OTHER WIND DIRECTIONS 2008/08/ CALM WIND SITUATION** 2008/08/ WIND, DIRECTLY FROM THE SOURCE 2009/02/23-03/ ALL OTHER WIND DIRECTIONS 2009/02/23-03/ CALM WIND SITUATION** 2009/02/23-03/ WIND, DIRECTLY FROM THE SOURCE 2009/02/23-03/ ALL OTHER WIND DIRECTIONS 2009/02/23-03/ CALM WIND SITUATION** 2009/02/23-03/ WIND, DIRECTLY FROM THE SOURCE 2009/11/11-12/ ALL OTHER WIND DIRECTIONS 2009/11/11-12/ CALM WIND SITUATION** 2009/11/11-12/ ** The wind speed is below 0,5 km/h.

11 METHODS A number of different risk estimates for PAH has been made, based primarily on using BaP as the index compound. Quantitative cancer risk estimates are summarized in the following table: Table 4 - Summary of unit risk estimates for BaP and for PAHs with BaP as the indicator substance (life-time risk per ng/m 3 of BaP) (Bostrom et al. 2002)

12 METHODS The increased risk for lung cancer among coke-oven workers is used for the quantitative risk assessment of PAHs with BaP as indicator substance by WHO in the Air Quality Guidelines for Europe (WHO 1987, 2000) Assuming a 0.71% content of BaP in benzene-soluble coke-oven emissions, it can be estimated a lifetime risk of respiratory cancer of 8.7x10-5 per ng/m 3 BaP This risk assessment would imply that about 9 per 100,000 exposed people may die from lung cancer as a result of spending a lifetime in ambient air containing an average level of 1 ng/m 3 BaP mixed all the other PAHs and relates substances in coke-oven emissions

13 METHODS Incremental Lifetime Cancer Risk (ILCR) For carginogens (cancer risk), the estimate exposure was multiplied by unit risk to derive an estimate of the potential Incremental Lifetime Cancer Risk (ILCR): ILCR=Exposure (ng/m 3 ) x Unit Risk (ng/m 3 ) - Probability of an individual to developing cancer over a life-time - Expressed as 1 in one million, , or 10-6 In this study, using BaP as indicator of general PAH mixtures from emissions of coke ovens and similar combustion processes in urban air, a lifetime risk of lung cancer of 8.7 x 10-5 was applied.

14 RESULTS Annual mean concentrations of BaP: 1.31 ng/m 3 (surrounding industrial area-tamburi) WHO Unit Risk: 8.7 x 10-5 per 1 ng/m 3 di BaP: Incremental Lifetime Cancer Risk 8.7 x 10-5 (ng/m 3 ) x 1.3 (ng/m 3 )= 11.3 x 10-5 considered as study population residents in Tamburi area (near industrial site) in 2009 Lifetime risk estimates of lung cancer associated with an exposure to 1.31 BaP (ng/m 3 ) is: 11.3 x 10-5 x = 1.99

15 INTERPRETATION AND CONCLUSION When are cleanup/controls needed? Cancer risks will be considered essentially negligible where the estimate ILCR is 1 in 100,000 (<= 1x10-5 ). If the ILCR is greater than 1x10-5, the risk assessment should either be refined and/or risk management measures should be taken. US EPA considers excess cancer risks that are below about 1 chance in 1,000,000 ( or 1E-06) to be so small as to be negligible, and risks above 1E-04 to be sufficiently large that some sort of remediation is desirable. Risk Assessment Guidance for Superfund, 1989

16 THANK YOU FOR YOUR ATTENTION MARIA SERINELLI Direzione Generale - ARPA Puglia Corso Trieste, BARI tel fax cell m.serinelli@arpa.puglia.it