Arsenicals and lung cancer

132

Occupationalhealth--Fd Costnrr.Toxicol. Vol. 19. no. 1

chlorobenzene in rhesus monkeys ere investigated in faeces was about twice that in the urine. The blood 7 the study cited above. and tissue distributions of pentachlorobenzene were Two male and two female rhesus monkeys were similar to those reported in rhesus monkeys given a each given a single oral dose of 05 mg [i4Cjpentasingle oral dose of hexachlorobenzene, but pentachlorobenzenefig body weight. It was found that chlorobenzene was metabolized more rapidly than about 95’1, of the dose was absorbed, with peak blood hexachlorobenzene (Rozman et al. Toxic. appl. Pharlevelsof pentachlorobenzene occurring between 2 and mat. 1978, 45, 293). Pentachlorophenol, 2,3,4,5tetra4.5 hr after treatment. The highest tissue concen- chlorophenol, 2,3.5,6-tetrachlorophenol and 1,2,3,4trations of pentachlorobenzene 40 days after treat- tetrachlorobenzene were identified as metabolites of ment were in the fat and bone marrow, followed by pentachlorobenzene in both males and females. The those in the lymph nodes, thymus. adrenal cortex and phenolic metabolites seemed to be restricted to the large-intestine. Only about 40 and 33”~ of the dose blood, kidney and urine, while 1,2,3+tetrachlorohad been excreted by the males and females. respect- benzene was detected only in the liver. This suggested ively. 40 days after treatment and it was estimated that biodegradation of pentachlorobenzene does not that the half-life of pentachlorobenzene in the rhesus occur in the liver. monkey was 2-3 months. The amount excreted in the

OCCUPATIONAL Arsenicalsand lung cancer Mabuchi. K., Lilienfeld. A. M. & Snell. L. M. (1979). Lung cancer among pesticide workers exposed to inorganic arsenicals.Archs envir. Hkh 34, 3 12. Epidemiological studies have revealed a correlation between the incidence of lung. lymphatic and skin cancers and exposure to inorganic arsenic. The mortality study cited above was carried out following a preliminary investigation that suggested an excess mortality from cancers of the lung and lymphatic tissuesamong workers who had retired from a factory in which they had been exposed to high atmospheric levels of inorganic arsenicals during the manufacture and packaging of pesticides. The incidence of mortality was determined among 86.9”. of 1050 men and 668”,, of 343 women who had been employed at the plant for varying periods between 1946 and 1977. The workers were grouped according to estimates of their degree of exposure to arsenicals and non-arsenicals. The observed number of deaths from all causes(197 males and 43 females) was not greater than expected, but amongst males significantly higher standard mortality ratios (SMRs) for lung cancer and anaemia were recorded (although there were only two cases of anaemia). Unlike the preliminary study, this study did not indicate an excess of deaths from lymphosarcoma. Significantly increased SMRs for lung cancer occurred among men employed predominantly in producing arsenicals (although not in the group employed entirely in such production) and also among those first employed before 1946 and those employed for 25 yr or more. No data concerning smoking habits were available but the SMRs for causes of death, other than lung cancer. that are strongly associated with smoking were not significantly increased. Furthermore, the pattern of SMRs for lung cancer was unlikely to be explained by smoking habits alone. An increasing gradient in the SMR for lung cancer among workers predominantly exposed to arsenicals was observed with increasing length of exposure both among those first employed before 1946 and among those first employed between 1946 and 1954. Such a dose-res-

HEALTH

ponse relationship was not seen in those employees predominantly exposed to non-arsenicals. The lack of a demonstrable excessof lung cancer in those exposed to arsenicals alone suggested a synergistic effect between arsenic& and non-arsenicals although further analysis of the data did not support this indication. Monitoring nickel levels Morgan, L. G. & Rouge, P. J. C. (1979). A study into the correlation between atmospheric and biological monitoring of nickel in nickel refinery workers. Alan. occup. Hyg. 22, 3 I 1. The hazards to workers in the nickel industry are well documented (Cited in F.C.T. 1974, 12, 428; ibid 1977. 15, 362). Monitoring personal exposure to carcinogens such as nickel makes an important contribution to the assessmentof the carcinogenic risk to individuals. Biological monitoring can also play an important role in preventing toxicological problems such as the dermatitic effects associated with nickel metal or salts (ibid 1976, 14, 366) and the acute toxicity of nickel carbonyl gas. Previous studies have indicated a lack of direct correlation between atmospheric exposure and nickel levels in the urine (ibid 1979, 17. 311). The study identified above further investigates the extent to which urinary nickel levels reflect exposure. The study involved 242 workers in a nickel refinery and 44 employees in a nearby petrochemical installation (controls). The test subjects worked in different departments between which the degree of exposure and type of nickel compound varied considerably. Each manual worker participating wore a personal air sampler for the duration of his shift. Urine samples were carefully collected at the end of each shift. In the control group the mean urinary nickel content (corrected to 1.6 g creatinine/litre) was 28 /.@ litre which compared well with the in-house control group (researchdepartment staff) exposed to a mean of 0.02 mg Ni/m3 and having a mean urinary nickel content of 30pg/litre. Workers in the chemical products department (examined twice) were exposed to concen-