International Journal of Environmental Science and Development, Vol. 4, No. 4, August assessment,

Transcription

1 Iteratoal Joural of Evrometal Scece ad Developmet, Vol. 4, No. 4, August 01 The Use of Epdemologcal Studes for Health Rsk Assessmet Kev Fog-Rey Lu, We-Ru Che, Yu-Che Yeh, L-We Chag, ad Yug-Shue She estmate the amout of a chemcal that s lkely to result a partcular health effect humas. I exposure assessmet, scetsts attempt to determe how log people were exposed to a chemcal; how much of the chemcal they were exposed to; whether the exposure was cotuous or termttet; ad how people were exposed - through eatg, drkg water ad other lquds, breathg, or sk cotact. The last step rsk assessmet brgs together the formato developed the prevous three steps to estmate the rsk of health effects a exposed populato. I the rsk characterzato step, scetsts aalyze the formato developed durg the exposure ad dose-respose assessmets to descrbe the resultg health rsks that are expected to occur the exposed populato. Ths formato s preseted dfferet ways for cacer ad o-cacer health effects. Although the secod step refers to the dose-respose relatoshp, the same prcples geerally apply for studes where the exposure s to a cocetrato of the aget (e.g., arbore cocetratos appled halato exposure studes), ad the resultg formato s referred to as the cocetrato-respose relatoshp. Usually, the relatoshp s based o observed data from huma clcal trals, epdemologc studes, amal tests ad cell studes, whch order also represets the order of ther precsos the dose-respose relatoshp, from better to worse. Nachma et al. [] ad Raffaele et al. [] have dscussed the use of epdemologc data HRA ad hghlghted some of the advatages ad lmtatos. Nachma et al. [] leared the lessos from some case studes ad suggested the use of epdemologc data to determe ocacer quattatve dose-respose relatoshps. Raffaele et al. [] also leared the lessos from ther case studes ad detfed a umber of mportat beefts to be gaed by usg epdemology data HRA: 1) detfcato of specfc huma health effects that were ot detfed amal models (e.g., orgac arsec); ) affrmato of the huma relevace of effects detfed amal models (e.g., eurodevelopmetal effects see wth chlorpyrfos); ) ablty to evaluate health effects for whch amal models are uavalable or lmted (e.g., orgac arsec ad cacer, pestcdes ad parkso s dsease); 4) evaluato of health effects the rage of expected huma exposures (e.g., orgac arsec); 5) utlty of bomotorg formato (chlorpyrfos). They also detfed a umber of mportat barrers: 1) dffculty covertg huma bomotorg formato to exposure levels that ca be cofdetly assocated wth a specfc hazard (dffcultes related both to back-calculatg from measured tssue levels to exposure levels as well as to uderstadg the source of measured metaboltes [.e. drect Abstract The hazard quotet (HQ), the rato of the take of the substace to ts referece dose, s usually used the health rsk assessmet (HRA) of a ocarcer substace. However, the values of HQ caot form ay specfc huma health effect. Compared to HQ, usg epdemologcal studes HRA ca mprove the defect. Ths study attempts to exame the potetal of the use of epdemologcal studes for HRA. Prevous epdemologcal studes help to costruct the lear cocetrato-respose relatoshps betwee ar pollutats ad assocated dseases ad two case studes are used to demostrate ths method. Idex Terms Epdemologcal assessmet, ar polluto, sadstorm. studes, health rsk I. INTRODUCTION A huma health rsk assessmet (HRA) s the process to estmate the ature ad probablty of adverse health effects humas who may be exposed to chemcals cotamated evrometal meda, ow or the future. Huma health rsk assessmet cludes 4 basc steps (Fg. 1): hazard detfcato, dose-respose assessmet, exposure assessmet ad rsk characterzato. Fg. 1. The four basc steps health rsk assessmet [1]. I the frst step, hazard detfcato, scetsts determe the types of health problems a chemcal could cause by revewg studes of ts effects humas ad laboratory amals. I dose-respose assessmet, scetsts evaluate the formato obtaed durg the hazard detfcato step to Mauscrpt receved Jauary 1, 01; revsed March 1, 01. Kev Fog-Rey Lu, We-Ru Che, Yu-Che Yeh, L-We Chag are wth the Departmet of Safety, Health ad Evrometal Egeerg, Mg Ch Uversty of Techology, New Tape Cty, Tawa (e-mal: kevlu@mal.mcut.edu.tw; U @mal.mcut.edu.tw; U @mal.mcut.edu.tw; U981670@mal.mcut.edu.tw). Y. S. She s wth the Holstc Educato Ceter, Mackay Medcal College, New Tape Cty, Tawa (e-mal: ysshe@mmc. edu.tw). DOI: /IJESD.01.V

2 Iteratoal Joural of Evrometal Scece ad Developmet, Vol. 4, No. 4, August 01 exposure to metabolte versus products of teral metabolsm], chlorpyrfos); ) dffculty detfyg exposed populatos (both wth respect to detfyg the specfc compouds to whch exposure occurred ad whch dvduals were exposed; parkso' dsease ad pestcdes); ) dffculty solatg specfc exposures (both routes of exposure ad quatfcato of exposure; all three examples); 4) cocers regardg approprateess of evaluated populato ( the key arsec studes, cludg det, geetcs, alteratve exposure sources ad the ssue of the youger age of the cotrol group). Ths study attempts to exame the potetal of the use of epdemologcal studes for HRA. Accordg to some epdemologcal studes [4], [5], the lear cocetrato -respose relatoshps betwee ar pollutats ad assocated dseases are costructed ad they are thereby appled to two case studes. The frst case detfes the morbdtes of the related dseases of the fve metropolses (Tape, New Tape, Tachug, Taa ad Kaohsug) Tawa durg 011, as show Fg. ; the secod case detfes the morbdtes of the related dseases durg a sadstorm of 010 from Cha. reversble arflow obstructo, ad brochospasm. Lug cacer s a dsease of ucotrolled cell growth tssues of the lug ad may lead to metastass to adjacet tssues. Peumoa s a flammatory codto of the lug, cludg lug parechyma ad abormal alveolar fllg wth flud. Emphysema s a log term, progressve dsease of the lug that prmarly causes shortess of breath. CAO s a type of pulmoary dsorder. COPD refers to a group of dseases that cause arflow blockage ad breathg-related problems, cludg chroc brochts, emphysema ad chroc obstructve arways dseases. Acute brochts typcally follows upper respratory tract fectos such as flueza ad ofte leads to peumoa. It s ot recogzed that chroc brochts ca tur to lug cacer or emphysema; however t may weake people so that they ca easly get lug cacer or emphysema. Usually, brochts ad asthma wll cause CAO ad they together wth emphysema ca result COPD. The above respratory dseases are related to some extet ad ther cause-effect relatoshps ca be establshed Fg.. Fg.. HRA structure for ar polluto [4] B. Dose Respose Assessmet The relatoshps betwee huma morbdty or mortalty ad the four ar pollutats have bee dscussed Lu ad hs colleagues' work [4]. Each crease 100 μg/m of TSP results a 6.58% crease mortalty; a cremetal dfferece of 100 μg/m (0.049 ppm) of NO s assocated wth a.95% crease mortalty ad a 6.6% crease brochts morbdty; a elevato of SO of 100 μg/m (0.05 ppm) results addtoal mortalty ad brochts morbdty by 8. ad 6.6%, respectvely. Each 10 μg/m cremet of PM10 ( μg/m of TSP) leads to a 1.4% crease morbdtes of cardovascular dseases ad a.4% crease brochts ad asthma. Every addtoal 1 ppm of CO wll crease mortalty by.57% ad cardovascular dseases by 4.6%; ad each cremetal dfferece of ppm of NO wll result a 1.8% crease morbdty of cardovascular dseases. I Tawa, the 005 aual mea cocetratos of TSP, SO, NO ad CO are 9.97μg/m, 0.005, ad 0.54 ppm, respectvely. I that year, the morbdtes of peumoa, cardovascular dseases, lug cacer, asthma, emphysema, COPD, CAO, brochts ad ar qualty-related mortalty are.01, 7.8, 0.1,.65, 0.11,.9, 0.96, 4.1 ad 0.18%, respectvely. Accordgly, the Fg.. Tawa map. II. METHODS AND MATERIALS A. Hazard Idetfcato The major ar pollutats are total suspeded partculates (TSP), sulfur doxde (SO), troge doxde (NO) ad carbo mooxde (CO). Accordg to Lu ad hs colleagues' work (01), the health effects of the four ar pollutats are show Fg.. TSP ca lead to cardovascular dseases, brochts, lug cacer, peumoa, emphysema, chroc obstructve pulmoary dsease (COPD), chroc arway obstructo (CAO) ad asthma; SO duces brochts, lug cacer, peumoa, emphysema, COPD ad CAO; NO ca cause cardovascular dseases, brochts, lug cacer, peumoa, emphysema ad COPD; ad exposure to CO ca result cardovascular dseases ad CAO. Brochts s flammato of the mucous membraes of the broch, the arways that carry arflow from the trachea to the lugs. Asthma s a commo chroc flammatory dsease of the arways characterzed by varable ad recurrg symptoms, 56

3 Iteratoal Joural of Evrometal Scece ad Developmet, Vol. 4, No. 4, August 01 fuctos of morbdty ad mortalty rates ca be derved for each ar pollutat, as show the last colum of Table I. P ( H E1 E E ) Asthma Mortalty SO Cardovascular Dseases [1 ] P( H E ) [1 P( H E )] [1 ] whe P( H E ) P( H E1 " E ) 1 P( H E ) [1 P( H E )] %[1.57% (CO 0.54) ] 1 4.6% 7.8%[1 (CO 0.54) ] 1 Mortalty 7.8[1 1.8% (NO 0.018) ] Cardovascular Dseases [1 P( H E )] P( E ) P( H E ) 4.1%[1 6.6% (NO 0.018) ] Brochts %[1.95% (NO 0.018) ] Mortalty 1 [1 ] 1 III. RESULTS: RISK CHARACTERIZATION A. Case 1 There are fve metropolses Tawa: Tape, New Tape, Tachug, Taa ad Kaohsug. Although the HQs of the ar polluto the fve ctes are below oe, whch meas t s ulkely to cause adverse health effects, but t s stll a terestg topc to uderstad the health effects the fve ctes, due to the ar polluto. Accordg to the data of 011 from the ar qualty measuremet statos, the frst case study detfes the morbdtes of the related dseases of the fve metropolses durg 011, ad the results are show from Fg. 4 to 11. The morbdty rates Table I are the sgle relatoshps betwee a pollutat ad a dsease. But t s very dffcult to fd the relatoshps betwee multple pollutats ad a dsease. To obta the overall morbdty of a dsease, a techology of the fuso of probablty has bee proposed [4]. For example, a dsease caused by three pollutats E1, E ad E s dsplayed as; P(E1 E E H) P(H E1 E E ) P(E1 E E ) 4.1%[1 9.94% (SO 0.005) ] Brochts CO P( H E ) P( E ) 7.8[1 1.4% (TSP 9.978) ].65%[1.4% (TSP 9.97) ] 0.081%[1 8.% (SO 0.005) ] 0.05 Cardovascular Dseases NO 4.1%[1.4% (TSP 9.97) ] Brochts TABLE I: AIR POLLUTANTS, HEALTH EFFECTS AND THEIR RELATIONSHIPS Ar Fuctos of mortalty or morbdty Iduced dsease pollutat rates 0.18%[1 6.58% (TSP 9.97) ] Mortalty 100 TSP P( H E ) P( E ) P(E1 E E H) P(E1 E E H) P(E1 E E H ) where P( E1 E E H ) P( E1 E E H ) ad assume that e1 e e are codtoal depedet, the P( E1 E E H ) P ( E1 E E H ) P( E1 H ) P( E H ) P( E H ) P ( H E1 ) P( H E ) P( H E ) P( E1 ) P( E ) P( E ) P( H E ) P( E ) Fg. 4. The morbdtes of the three dseases Tape, 011. Smlarly, B. Case I 010, there s severe sadstorm from Cha, lastg from March 1 to March. Accordg to the data from the Tashag ar qualty measuremet stato ( New Tape), the secod case study detfes the morbdtes of the related dseases durg the sadstorm. The results are show from Fg. 1 to 17. P ( E1 E E H ) P ( H E1 ) P ( H E ) P ( H E ) P ( E1 ) P ( E ) P ( E ) P ( H ) [1 P( H E1 )][1 P( H E )][1 P( H E )] P( E1 ) P( E ) P( E ) [1 ] [1 P( H E )] P( E ) [1 ] 57

4 Iteratoal Joural of Evrometal Scece ad Developmet, Vol. 4, No. 4, August 01 Fg. 10. The morbdtes of cardovascular dseases the fve ctes, Fg. 5. The morbdtes of the three dseases New Tape, 011. Fg. 11. The morbdtes of asthma the fve ctes, Fg. 6. The morbdtes of the three dseases Tachug, 011. Fg. 1. The morbdtes of brochts caused by PM10 durg the sadstorm ( ~). Fg. 7. The morbdtes of the three dseases Taa, 011. Fg. 8. The morbdtes of the three dseases Kaohsug, 011. Fg. 1. T The morbdtes of cardovascular dseases caused by PM10 durg the sadstorm ( ~). Fg. 9. The morbdtes of brochts the fve ctes, 011. Fg. 14. The morbdtes of asthma caused by PM10 durg the sadstorm ( ~). 58

5 Iteratoal Joural of Evrometal Scece ad Developmet, Vol. 4, No. 4, August 01 IV. DISCUSSION The frst case study reveals that the adverse health effects are more severe durg wter ad sprg tme. The sestve populato s vulerable the perod, especally the south part of Tawa. The secod case study shows the morbdtes of cardovascular dseases ad asthma dramatcally crease durg the sadstorm, prmarly due to heavy TM10 the ar. The sestve populato s suggested to stay doors or wear masks. ACKNOWLEDGMENT The authors would lke to thak the Natoal Scece Coucl of the Republc of Cha (Tawa) for facally supportg ths research uder Cotract NSC E MY. Fg. 15. The overall morbdtes of brochts durg the sadstorm ( ~). REFERENCES [1] [] [] Fg. 16. The overall morbdtes of cardovascular dseases durg the sadstorm ( ~). [4] [5] CEPA. Calfora Evrometal Protecto Agecy, Offce of Evrometal Health Hazard Assessmet. (01). A Gude to Health Rsk Assessmet. [Ole]. Avalable: K. E. Nachma, M. A. Fox, M. C. Sheeha, T. A. Burke, J. V. Rodrcks, ad T. J. Woodruff, Leveragg Epdemology to Improve Rsk Assessmet, The Ope Epdemology Joural, vol. 4, pp. -9, 011. K. C. Raffaele, S. V. Vulmr, ad T. F. Bateso, Beefts ad Barrers to Usg Epdemology Data Evrometal Rsk, The Ope Epdemology Joural, vol. 4, pp , 011. K. F. R. Lu, C. F. Lu, C. W. Che, ad Y. S. She, Applyg Bayesa belef etworks to health rsk assessmet, Stoch Evro Res Rsk Assess, vol. 6, pp , 01. K. F. R. Lu, C. F. Lu, C. W. Che, ad Y. S. She, Usg Bayesa belef etworks to support health rsk assessmet for sewer workers, Iteratoal Joural of Evrometal Scece ad Techology, vol.10, pp.85-94, 01. Kev Lu receved the B.S. degree 199 ad the Ph.D. degree 1998, both cvl egeerg from Natoal Cetral Uversty, Tawa. Curretly, he s a Assocate Professor the Departmet of Safety, Health ad Evrometal Egeerg, Mg Ch Uversty of Techology, Tawa. Hs research terest s the use of decso aalyss ad artfcal tellgece techques to evrometal maagemet ssues. Fg. 17. The overall morbdtes of asthma durg the sadstorm ( ~). 59