Document zo1NK8v8j4ajavbg7dMG3wBz

Y e f h r r 1 n n s t f i rI ] Carcinogenic Chemicals in the Occupational Environment Ahti Anttila', Markku Sallmen1, Kari Henuninki14 'Institute of Occupational Health, Topeliuksenkatu 41 a A, SF-00250 Helsinki, Finland sCenter for Nutrition and Toxicology, Karolinska Institute, Novum, 14157 Huddinge, Sweden Abstract: A survey of occupational carcinogensby the Institute of OccupationalHealth, Finland shows that more than 100 000 workers are exposed to carcinogenicsubstances. The most common exposures are silica, wood dust, tobacco smoke and lead compounds. Based on biological monitoring of workers over the years it appears that overall lead exposure has decreased but exposure to styrene, trichloroethylene and tetrachloroethylene has decreased only slightly or remained constant. The biological monitoring data are based on samples sent by the workplaces on their initiative presenting no scientificallyselected sampling. Thus due caution is needed in the interpretation of the trends. * For more than half of the chemicals or agents, classified by the International Agency for Research on Cancer as human carcinogens (International Agency for Research on Cancer, 1987), the evidence is coming from occupational exposure. In addition to specific chemicals or agents IARC has considered several occupations causing a risk of cancer even though the chemicals or agents have not been specified, usually due to exposure to a mixture of chemicals. Cancer is caused by exposures one or more decades ago, due to a long latency in the development of the disease. Thus many occupational carcinogens, classified by IARC, were detected among workers who were exposed usually between the 1920's and 1960's. Even though many principles in technology have not dramatically changed over the decades in western industrialized countries, the arrangement of work has. Automation, closed systems and robots have in many instances decreased the exposures dramatically in spite of increased output. The aim of this paper is to give an overview of the knowledge of occupational exposure to carcinogenic substances in Finland. It is important but difficult, due to sparsity of data, to review exposure time trends. On the other hand many new chemicals, with unknown toxicological properties, have been taken into use. As typical present day exposures are to low concentrations of many chemicals, short team tests for genotoxic activity and molecular epidemiology studies in exposed workers are recommendable tools in future cancer prevention (Farmer et ah, 1987; Perera, 1987;Bartsch et al.,1988). Occupational Exposure to Carcinogens Finland (population 5 million, total work force 2.4 million) instituted legislation concerning registration of workers exposed to listed carcinogens (IARCclasses 1, 2A and 2B compounds with some important omissions such as formaldehyde) since 1978 (Alho et al.,1988). Employers are sending the reports annually to the Institute of Occupational Health where the registry (ASA) is maintained. The number of registered workers has increased steadily, probably indicating improving coverage. However, there are still severe underreporting in some areas, such as construction (asbestos being the main carcinogen), whereas in some other areas reporting is vigilant, e.g. laboratory personnel has been notified to the register even if small amount of a carcinogen have been used as a standard compound in well-controlled circumstances. Over the years the reporting principles have become more uniform, but, of course, the register only gives soma idea on important carcinogens and their users. In 1989 altogether 17 118 workers from 1899 departments were announced in the Finnish ASA registry. Fig. 1 shows the most commonly notified jobs in 1989 (Institute of Occupational Health, 1991). The most common occupations are engine repair men (17% of the total), welders (14 %), metal plate workers (7 %) and engine installers (7 %). Miscellaneous job titles constituted 44 % of all the jobs. Fig. 2 shows the most commonly reported carcinogenic agents which are chromium 6-valent compounds, nickel compounds, asbestos and benzene. The ASA registry is a n administrative institution and does not, due to underreporting, jive a true number of the exposed workers. An extensive project at the Finnish Institute of Occupational Health has been carried out aiming at estimates of chemical exposure in the workplaces in Finland. Table 1 is using the data from this project, as far as available, in the estimation of the number and extent of exposure to suspected carcinogens in the Finnish workplace. Table 1only lists J s. 70 ANTTILA ET AL. Fig. l.The most commonly notifiedjobs in the Finnish ASA registry in 1989.The figure is based on 17,118 announcements in ASA. (Institute of Occupational Health, 1991). those agents to which 1000 or more workers are exposed. Silica and wood dust, tobacco smoke, lead, hexavalent chromium and nickel compounds, mineral fibers and asbestos, polycyclic aromatic hydrocarbons and formaldehyde each affect 10 000 workers or more at concentrations indicated. In the project industrial hygienic measurements, mainly from the years 1980 1985 and biological monitoring data from 1987, were collected. The concentrations given in table 1 are estimates of time weighted averages. The estimates are usually based on several (10-300)industrial hygienic measurements collected at the project. Yet it must be admitted that the estimates are crude. For certain compounds, such as benzene, trichloroethylene, tetrachloroethylene and hydrazine, the exposures are periodic and it is particularly difficult to give any average exposure levels. In all, the exposure levels should be taken with due reservations. In addition to the compounds listed in Table 1. close to 1000 workers are exposed to acrylonitrile, aniline, carbon tetrachloride, chlordane, cyclophosphamide, 1,2dibromoethane, dimethyl sulphate, dioxane, Fig. 2. The most commonly notified carcinogenic agents in the Finnish ASA-registry in 1989. The figure is based on 17,118 announcements in ASA. (Institute of Occupational Health, 1991). epichlorohydrine, ethylene oxide, ethylene thiourea, 4,4methylene-bis (2-chloroaniline) or MOCA. polychlorinated biphenyls and thiourea. Earlier chlorophenols were extensively used in the impregnation of wood and several thousand workers were involved. It is difficult to estimate the total number of workers exposed to carcinogens because of mixed exposures. However, among the large groups, exposed to silica, wood dust, tobacco smoke and lead there are overlaps thus adding up the total over 100 000. Biological Monitoring of Exposure Several exposures have been monitored from biological samples at the Finnish Institute of Occupational Health over the years. Styrene, tetrachloroethylene, trichloroethylene, methylene chloride, benzene, hexane, chlorophenols, PCB's, arsenic compounds, cadmium, chromium, lead, nickel and nicotine (tobacco smoke) are the most commonly monitored carcinogenic exposures. Usually the measurements are samples sent by the employers, and thus they do not constitute a random sample. Any conclusions from the files of biologically monitored workers should be drawn with due consideration. Blood lead has been measured most extensively. In connection with a retrospective study, about 63 000 blood lead (B-Pb) measurements, conducted during 1973-1982 on approximately 22 000 workers from occupational lead exposure, have been transferred into a computer from the laboratory documents. In the same context, monitoring data on six organic solvents was also collected (nearly 22 000 measurements, 9 000 workers), including styrene (U-ManA), tetrachloroethylene (B-Per) and trichloroethylene (UTCA) (Taskinen, 1990;Lindbohm, 1991) .The number of msasuren.enta from other carcinogenic agents during the same time was considered too small for the study of reproductive hazards, and the data was not recorded. Lead. Fig. 3 shows blood lead concentrations for men and women between 1973-1982 in the monitoring data. According to the regulations, if the B-Pb of any worker in the workplace exceeds 2 pmol/1 (= 40 pg/dl), all workers in similar tasks should be monitored. If very high B-Pb levels (>3 pmol/1) are found, the individuals should be monitored several times a year (Hernberg, 1984). To avoid overrepresentation of such repeated measurement, an individual is only entered once annually to Fig. 3 with the highest B-Pb result. The median values decreased from 13 to 0.7 pmol/1 for men, which was a highly significant decrease (p < 0.0001, regression analysis). The highest values decreased from 6-8pmol/l to 44.5 pmol/l among men and from 5-5.5 gmol/1 to about 2.5 pmol/1 among women. The most clear-cut decrease took place during the firs5 wer dec: sim ind of E B-r CARCINOGENIC CHEMICALS IN THE OCCUPATIONAL ENVIRONMENT s. 71 4 first half of the 1970's in the industries where the levels decrease was also evident in glass and pottery V, sr were high in 1973. The industries where marked decreases took place are shown in Fig. 4, including lead manufacturing, graphicsindustry, paint manufacturing and motor vehicle inspection. le smelting, founding, scrap metal and storage battery In some industries the decrease has been modest as ru industries, and WC-plastics production. The estimation shown in Fig. 5: chemicals and ammunition of B-Pb level is based on the annual mean of individual manufacture, and car repair works. In the chemical T8 8-Pb results during each year when measured. A rapid industry the highest exposures were related to the S. a, Table 1. >B Occupational exposure to suspected carcinogens in Finland Exposure No exposed Branch (examples) Concentration (jig/m5) Sil-im 50000 Construction, founding, mining u h Wood dust 20000 Sawmills, carpentry ICO 1000 Tobacco smoke 20000 Bars, restaurants, airplanes 0.01 (as benzota)pyrene) > e Lead comp. 20000 Engineering, founding, car repair, battery 10 >. manufacturing e 3 Mineral fibers 10000 Construction 0.1 F/cms y Chromium 6 comp. 10000 Steel production, cutting, plating, welding, 50 spray painting Asbestos 10000 Construction,maintenance, brake repair O.lF/cm3 i ) Nickel comp. 10000 Steel production, cutting, plating, welding 10 i PAH 10000 Steel production, coking, founding, trucking 0.1 (asbenzo(a)pyrene) > Formaldehyde 10000 Plywood, particleboard production, laquering 500 Benzene 5000 Oil refining, gasoline distribution 500 Arsenic comp. Styrene Radon 5000 3000 2000 Impregnation use of wood, glass industry, copper production Lamination Mining, underground work 10 100000 1000 Bq/m3 Nitrosoamines 2000 Rubber, leather, metal industry 1 Cadmium comp. 2000 Hard soldering, founding, plastics production 1 Tetrachloroethylene 2000 Dry cleaning, degreasing 1000 Hydrazine Methylene chloride. 2000 2000 Energy production Pharmaceutical industry, paint removal 10 ' 10000 Trichloroethylene 1000 Degreasing 1000 Chloroform 1000 Pharmaceutical industry 1000 Vinyl chloride 1000 PVC production, processing 500 s. 72 ANTTILAET AL. manufacture and repair of storage tanks. In a small group of workers the B-Pb levels did not change during the study period. In car repair the exposure did typically not exceed the level 1.9 pmol/1. The measurements cover only a small part of the car repair industry. In 1987,the highest B-Pb values were below 2 pmol/1 in the PVC plastics manufacturing (Jaakkola & Anttila, 1992) .In the storage battery industry no value exceeded 3 pmot/1, In foundries the highest values still exceeded 3 pmol/1, as well as in the railroad machine shops, miscellaneous metal and engineering industry, and various casting and torch-cutting works and in car radiator repair. Neither of the two large lead smelting enterprises were operating during that year. High B-Pb values were occasionally found also in stevedoresand in the demolition of outdated explosives, but in thesejobs there were, however, only few exposed workers. styrene. The number of workers monitored for styrene exposure increased rapidly from a few tens in 1973 and 1974 to 600-700 in the eighties. About one quarter of the measurements has been conducted on women. Fig. 6 shows the percentiles of the yearly urine mandelic acid measurements from 1974-83 and 1987. " he overall exposure level of the workers monitored for styrene was high. Women were, on average, more exposed than men. About 60% of the measurements conducted on women, and about 35% conducted on men exceeded the present Finnish reference value of the exposed (3.2mmol/l). In 1987 the maximum mandelic acid concentrations were at the same level than in the early eighties. Upper quartiles and medians were somewhat lower in 1987 than in 1983. The overall decrease in exposure levels during seventies and eighties, as a consequence of technical improvement of ventilation systems, has been slow. The working methods have in large respects re or JlT w< ^.te yf SC tl (I d IT d a a UMOL/L MEN UMOL/L 10 - 8 WOMEN L P25 P99 median " " maximum - P75 0 ------------------------------------------------------------------------1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 P25 P99 median maximum P75 Fig. 3. Percentiles of the highest individual B-Pb results during the calendar years 1973-1982. Each year about 2,3004,90Qnen and 300-630 women were monitored for lead. CARCINOGENIC CHEMICALS IN THE OCCUPATIONAL ENVIRONMENT a. 73 remained unchanged (SaSmanen et al,, 1991). available in the data before 1987, but the fur washers ire Because there is no information on the industry, (1.2-7.5 gmol/1, geometric mean 2.7) and laundry to occupation or work tasks in the data ftcm 1974-83, the workers (0-14.0 gmol/1, geometric mean 0.8) had the he reason for the difference in exposure levels by sex is highest exposure levels in 1987 (Rantala et al.,1992). unknown. There may be more handlaminators among The industrial hygienic measurements in 1982-1985 ne women than among men. indicated high short-term exposure in metal spray 37. washing work, 400*103 gg/m3 on average. 'or Tetrachloroethylene. -re The number of monitored workers for Trichloroethylene. its tetrachloroethylene exposure has been around 150 per Biological monitoring for trichloroethylene exposure has an year during 1977-83 and in 1987, if only morning been conducted at the Institute since 1965. The amount he samples are included. of monitored workers was in its maximum in 1970. Only few workers had monitoring results higher than After that trichloroethylene has been replaced by is the Finnish reference value of exposed i.e 6.0 pmol/1 tetrachloroethylene in dry cleaning work. In metal er (Fig. 7). There is no clear decrease in exposure levels industry, on the other hand trichloroethylene has been 37 during the period. The women were as exposed as the replaced by 1,1,1-trichloroethane as degreasing agent. Is men although in the occupations there certainly is About 45% of the monitored workers were women. of differences by sex. The washers are exclusively women The Finnish reference value of exposed (U-TCA 360 in and the men work as service-men in the laundries. The pmoftl) were exceeded by 10% of the workers. The ts amount of workers in different industries is not yearly maximum exposure levels vary very much r----- LEAD SMELTING MEN a ---- FOUNDRIES MEN PVC PLASTICS INDUSTRY MEN if I STORAGE BATTERY FACTORIES MEN woul r- --------- METAL SCRAP BUSINESS MEN UMOLA PA1LROAO MACHIHE SHOPS MEN * n n N n n n M ii mm * mn u n m n n m m *i mm * r m r* m -n ra im m mm MAXIMUM 95TH-PERCENTILE UPPER QUARTILE MEDIAN Fig. 4. The percentile of the individual yearly B-Pb mean values during 1973-1982 within selected industries. The number of workers measured each year shows on top of the bar 3. 74 ANTTILA ET AL. (Figure 8). The difference between the most exposed worker and the second can be many thousands pmols per liter. The upper quartiles and medians indicate that the typical exposure levels for trichloroethylene are decreasing during this period. The medians for both sexes were around 100 pmol/1 in the middle sixties and about 40 to 50 pmol/1 in the beginning of eighties. The maximum urine trichloroacetic acid concentrations in 1987 was 860 pmol/1, suggesting a clear decrease compared to the earlier years. The highest exposure levelsin 1986-1988were found among metal degreasers (0-860 pmol/l, geometric mean 84) and painters (0-715pmol/l, geometric mean 70)(Rantala et al., 1992). Conclusions Based on the extensive survey of occupational carcinogens at the Institute of Occupational Health, Finland over 100 000 workers are estimated to be exposed to carcinogens, the most prevalent of which are silica, wood dust, tobacco smoke and lead compounds. Some ideas about the trends in exposure can be obtained from historical data on biological monitoring, recorded at the Institute from occupational exposure to lead and some solvents. In the case of lead the register covers about 10% - 25% of all lead-exposed workers. The coverage is different in various industries. Workers in storage battery industries, lead smelting, metal foundries, railroad machine shop and the chemical industry were monitored most frequently. As a whole a decreasing trend in B-Pb was seen between 1973-82. The periodic medical check-ups and compulsory lead-free periods of the high-exposed workers had an impact to lower B-Pb values in the plants with very high lead exposure. The decrease reflects technological development and hygienic improvements in the Finnish industry. Automation, closed and half-open emission sources, conveyors, improved ventilation, personal protective equipment AMMUNITION MANUFACTURE MEN UMOl/l AMMUNITION MANUFACTURE WOMEN UMOUi CHEMICALS MANUFACTURING MEN via N H n n m n i* m MOTOR CAR REPAIR SHOPS MEN AUTOMOBILE SHOPS MEN CAR RADIATOR REPAIR MEN '00 0 Fi m In w* a: 1! cl P c; ir L e t C C C ( 1 Fig. 5. The percentile of the individual yearly B*Pb mean values during 1973-1982 within selected industries. The number of workers measured each year shows on top of the bar. C T3 T ) _ CARCINOGENIC CHEMICALS IN THE OCCUPATIONAL ENVIRONMENT Styrene Trichloroethylene 8. 75 'e U-ManA(umol/1) je mnnn a 10000 S, :o te n H \\ e 74 75 78 77 78 79 80 ai e.~83 87 e Year as 87 69 71 73 75 77 79 81 Year 87 c Fig. 6. The percentiles of urine mandelic acid(U-ManA) Fig. 8. The percentiles of urine trichloroacetic acid (U-TCA) i, measurements in 1974-1983 and 1987 at the Finnish measurements in 1965-1982 and 1987, at the Finnish t Institute of Occupational Health. Each year 100-700 workers Institute of Occupational Health. The median in 1987 <50 t were monitored. micromol/1, estimated value presented. 100-570 workers were monitored each year. and improved personal hygiene became common during 1970's. The plants were modernized. The materials were changed to safer ones. These are the common procedures for the reduction of exposure to occupational carcinogens, applicable to other exposures, and essential in the prevention of occupational cancer in general. Lead exposure diminished due to materials development especially in PVC plastics, paints, glass and pottery. In the graphics industry, the technology in type-setting have not substantially changed, the exposures have remained fairly constant. The occurrence of individual monitoring data and the large occupational survey give unique possibilities for future epidemiological studies on cancer among workers handling carcinogensin their occupational environment. changed. In case of organic solvents the trends were not as clear-cut. For styrene and trichloroethylene a slight decrease while no change for tetrachloroethylene was observed. One has to be cautious in drawing conclusions from the relatively few and non-random measurements available. The data suggests, however, that as the work Acknowledgements The authors are grateful to Drs. Antti Tossavainen andPirjo Heikkila for comments. References processes and other arrangements for these solvents Tetrachloroethylene Alho, J., T. Kauppinen & E. Sundquist: Use of exposure registration in the prevention of occupational cancer in Finland. Am. J. Ind. Med, 1988,13, 581-592. , B-Perlymol/D _ Bartsch, H.( K. Hemminki & I.K O'Neill (ed.3): Methods for detecting DNA damaging agents in humans: applications in cancer epidemiology and prevention (lAJtC Scientific Publication No. 89). International Agency for Research on Cancer, Lyon, 1988. Farmer, P.H., H.G. Neumann & D. -Henschler; Estimation of exposure of man to substances reacting covalently with macromolecules. Arch. Toxicol, 1987,60, 251-260. * o.i 17 78 79 90 8l 82 83 0 8? Year pig. 7. The percentiles of blood tetrachloroethylene(B-Per) measurements in 1977-1983 and 1987, at the Finnish Institute of Occupational Health; only morning samples included. 100-200 workers were monitored each year. Hernberg, S.: Lead. In: Eds.: Aitio, A, V. Riihimaki & H. Vainio. Biological monitoring and surveillance of workers exposed to chemicals. Hemisphere publishing company, New York, 1984, pp.19-27. Institute of Occupational Health: ASA 1989, Institute of & s. 76 ANTTILA ET AL. Occupational Health, Reviews No. 115. (In Finnish). Institute of Occupational Health, Helsinki, 1991. International Agency for Research on Cancer: Overall evaluations of carcinogenicity: an updating of 1AEC monogmphs 1-42.1ARC monographs on the evaluation of carcinogenic risks to humans, suppl. 7.International Agency for Research on Cancer, Lyon, 1987. Jaakkola, J. & A Anttila: lead Exposures at work, No. 26. (Lyijy. Altisteet tyossa No. 26). (In Finnish). Institute of Occupational Health & Finnish Work Environment Fund, Helsinki, 1992. Lindbohm, M-L.: Parental occupational exposure and spontaneous abortion.Academic dissertation, University of Tampere, Tampere, 1991. Perera, FP.: Molecular cancer epidemiology: a new tool in cancer prevention. J. Natl. Cancer Inst 1987, 78, 887-898. Rantala, K, H. Riipinen & A Anttila: Halogenated hydrocarbons. Exposures at work, No. 22. (Halogeenikiilivedyt Altisteet tyossa no. 22). (In Finnish). Institute of Occupational Health & Finnish Work Environment Fund, Helsinki, 1992. S&amanen, A, A Anttila & P. Pfaffli: Styrene. Exposures at work, No. 10. (StyreenL Altisteet tyosa no. 10). (In Finnic. Institute of Occupational Health & Finnish Work Environment Fund, Helsinki, 1991. Taskinen, H.: Occupational risks of spontaneous abortion and congenital malformation. Academic dissertation, University of Tampere, Tampere, 1990. E d e C S r F F r c P 1 ( I r ( i