[NIGHT SHIFT WORK AND HEALTH DISORDER RISK IN FEMALE WORKERS].

There was evaluated the risk to health in females employed in shift work, including night shifts. According to the data of periodical medical examinations health indices of 403 females employed in shift work, including night shifts, were compared with indices of 205 females--workers of administrative units of the same enterprise. Overall relative risk (RR) for the health disorder associated with the night shift was 1.2 (95%; confidence interval (CI): 1.09-1.28). A statistically significant increase in risk was observed in relation to uterine fibroids (OR 1.3; 95% CI: 1.06-1.54), mastopathy (OR 1.4; 95% CI: 1.2-1.6), inorganic sleep disorders (OR 8.8; 95% CI 2.6-29.8). At the boundary of the statistical significance there was the increase in the risk for obesity (OR 1.2; 95% C: 0.97-1.39), hypertension (OR 1.2; 95% CI, 0.9-1.5) and endometriosis (OR 1.5; 95% CI: 0.98-2.16). There was revealed an adverse effect of night shifts on the gestation course: ectopic pregnancy in the experimental group occurred 6.6 times more frequently than in the control group (95% CI: 0.87-50.2), and spontaneous abortion--1.7 times (95% CI: 0.95-3.22). The performed study has once again confirmed the negative impact of smoking on women's reproductive health: smoking women in the experimental group compared with the control group smokers had 2.7 times increased risk of uterine fibroids (within 1.06-7.0), the risk in non-smokers was significantly lower--1.2 (0.98-1.4). The findings suggest about a wide range of health problems related to employment on shift work, including night shifts, which indicates to the need for adoption of regulatory and preventive measures aimed to this professional group.

Parental occupation and other factors and cancer risk in children: I. Study methodology and non-occupational factors.

A population-based case-control study of risk factors for childhood cancer was conducted for 593 cases diagnosed over the period 1986-1988 in Moscow children 0 to 14 years of age. Two healthy controls to every case were selected from registers of local pediatric polyclinics by age, gender and residence. The parents of 593 cases and 1181 controls were interviewed face-to-face. Significantly higher odds ratios (OR) were associated with cancer in close relatives [OR 1.6; 95% confidence interval (CI) 1.3-1.9], any pathology associated with pregnancy (OR 2.9; 95% CI 2.4-3.6), including threatened miscarriage (OR 2.1; 95% CI 1.5-3.0), toxemia (OR 2.2; 95% CI 1.8-2.8) and hormone treatment during pregnancy (OR 2.2; 95% CI 1.0-4.5). Pre-term births were significantly associated with brain-cancer risk (6/1; OR 13.3; 95% CI 1.5-301.2). For low birth weight (< or = 2500 g) children born from full-term pregnancy, the OR for all cancers combined was 2.5 (23/22; 95% CI 1.4-4.7) and for leukemias 4.7 (9/4; 95% CI 1.4-16.5). In all, 100 cases and 151 controls had birth weight > or = 4000 g (OR 1.4; 95% CI 1.1-1.9). Risk of nephroblastoma was also significantly related to this factor (11/5; OR 5.1; 95% CI 1.6-16.4). A positive trend of OR with decreasing duration of breastfeeding was significant for all cancer combined (p < 0.05). Significantly higher OR were observed for dermatitis (12/6; OR 4.0; 95% CI 1.4-12.1) and viral hepatitis (40/22; OR 3.8; 95% CI 2.3-6.3) in child medical history.

Parental occupation and other factors and cancer risk in children: II. Occupational factors.

A population-based case-control study was conducted on 593 cancer cases in children from 0 to 14 years of age diagnosed in Moscow from 1986 to 1988. The study included 1181 healthy controls matched by age, gender and residence. Parental exposures prior to conception, including exposures to petroleum products, organic solvents, unspecified chemicals, soldering aerosols, ionizing radiation, electromagnetic fields (EMF), visual display units (VDU) and high temperature in the work environment, were significantly more frequent among the cases than among the controls (p < 0.05). Leukemia risk was associated with paternal exposure to ionizing radiation [odds ratio (OR) 6.7; 95% confidence interval (CI) 2.8-15.8], EMF (OR 4.6; 95% CI 1.8-11.9), VDU (OR 2.4; 95% CI 1.0-5.8) and unspecified chemicals (OR 2.0; 95% CI 1.02-4.1). Leukemia risk was also higher when mothers were exposed to solvents (OR 3.1; 95% CI 1.5-6.3), unspecified chemicals (OR 2.0; 95% CI 1.0-4.3), ionizing radiation (OR 10.3; 95% CI 1.3-83.4) and EMF (OR 5.2; 95% CI 1.6-16.8). Increased risk of non-Hodgkin's lymphoma was shown to be related to maternal exposure to oil products (OR 3.3; 95% CI 1.01-10.7) and unspecified chemicals (OR 3.3; 95% CI 1.01-10.7). Exposure to VDU was found to be associated with increased risk of neuroblastoma (6/1; OR 13.8; 95% CI 1.9-100.0).

Mortality and cancer incidence in a cohort of rubber workers in Moscow.

This study evaluated the mortality and cancer incidence of 1178 men and 2492 women who had worked at least 10 years in a large rubber manufacturing facility up to the cohort assembly period between 1 January 1979 and 31 December 1983. The follow-up period was from 1 January 1979 to 31 December 1988. For all causes of death no increase in risk was observed. The male workers had a nonsignificantly increased standardized mortality ratio (SMR) for all cancers [SMR 116, 95% confidence interval (95% CI) 90-151] and a significantly increased SMR for injuries (SMR 174, 95% CI 111-257). For the men the all-cancer standardized incidence ratio (SIR) was 146 (95% CI 119-172), and the SIR for brain cancer was significantly greater than 100 (SIR 500, 95% CI 233-767). Among the female workers only a significant excess risk for laryngeal tumors (SIR 1430, 95% CI 172-5160) was found. Because of the limited amount of data and the many subgroups formed, the occupational genesis of the cancer excess should not be overinterpreted. In addition, there was a possibility of confounding from smoking and other nonoccupational factors.

Carcinogens in rubber production in the Soviet Union.

In a preliminary phase of a broad research project on cancer among workers in a rubber footwear plant in Moscow, exposure to several known or potential carcinogens was assessed. There were high dust contents bearing both toxic substances and carcinogens. The highest concentrations of benzo[a]pyrene (500-14,400 micrograms) were found on the soot used as a filler, and the maximum N-dimethylnitrosamine (DMNA) level was measured in thiram (150-23,868 micrograms.kg-1). Air samples from the vulcanization process and the pressing of rubber goods showed BaP levels of up to 1.43 micrograms.m-3. In the work area where polyvinyl chloride was used, the mean vinyl chloride concentration was 0.21 (SE 0.06) mg.m-3. The mean value of the acrylonitrile concentrations in the workroom area was 0.19 (SE 0.07) mg.m-3. Very high levels of DMNA and N-diethylnitrosamine were measured in the preparatory shop in the winter.