Paternal occupation and Wilms'' tumour in offspring.

A case-control study was conducted to test the hypothesis that paternal occupation is a risk factor for Wilms' tumour in offspring. Occupations associated with exposure to lead (Pb) and to hydrocarbons were examined by computing odds ratios, all of which were greater than unity but not by a statistically significant margin. When painters were considered separately, children whose fathers had been so employed were six times more likely to develop Wilms' tumour than children whose fathers had other occupations. Like the results for the Pb and hydrocarbon related occupations, the estimated relative risk associated with painters did not reach statistical significance. Although these data require cautious interpretation because of the relatively small number of subjects, the results reported here are not wholly consistent with the results of the one previous study of paternal occupation and Wilms' tumour in offspring.     

Paternal occupation and brain cancer in offspring: a mortality-based case-control study

A mortality-based case-control study of selected risk factors for childhood brain tumors was undertaken. Ohio-born children who died from brain cancer during the 1959-1978 vicennium were compared to control children (of the same age, race, and sex) by using information obtained from the subjects' birth certificates. Differences between the case and the control children with respect to paternal occupation, the focus of the study, were examined. Controlling for the potentially confounding effects of several nonoccupational factors, case fathers were found more likely than control fathers to have been employed (at the time of birth of their children) in agriculture, in metal-related jobs, in structural work jobs in the construction industry, and in electrical assembling, installing, and repairing occupations in the machinery industry. Although the results must be interpreted with caution, the findings lend support to the hypothesis that parental occupation is a potential risk factor for childhood brain tumors.     

Congenital anomalies among the offspring of fire fighters

A case-control study has been conducted to determine the association between employment as a fire fighter and congenital heart defects among the offspring. Cases were fathers of all children born between 1979 and 1986 in Ontario, Canada, who were diagnosed with a cardiac congenital anomaly during the first year of life (n = 9340). Matched controls (n = 9340), defined as fathers whose child did not have a congenital anomaly, were randomly selected from the Ontario birth certificate file. In order to identify those fathers who had been employed as a fire fighter, the cases and controls were linked to a cohort of Metropolitan Toronto fire fighters. Eleven cases and nine controls worked as fire fighters, giving an odds ratio of 1.22 (95 percent confidence interval 0.46–3.33). This study had sufficient power to detect the level of risk reported in one previous study; however, these results do not support a hypothesis of elevated risk of cardiac congenital anomalies among the offspring of fire fighters. © 1996 Wiley-Liss, Inc.     

某有色金属企业1980～1999年职业伤害的流行病学研究

目的 掌握有色金属企业职业伤害分布特征，探索职业伤害发生规律和影响职业伤害发生的因素，为最大限度地控制和减少职业伤害提供科学依据。方法 用回顾性流行病学调查方法，调查某有色金属企业1980～1999年职业伤害发生情况和分布规律。结果 某有色金属企业1980～1999年发生职业伤害3831例。矿山3000例，工厂831例；男性3592例，女性239例；轻伤3630例，重伤104例，死亡57例。职业伤害在时间分布上有季节性特征。昼时分布有明显的集中趋势，高发于中班，圆形分布检验差异有显著性。人群分布以20～30岁年龄为高发人群，构成占40％以上，以20～25岁为最高点。工龄分布以1～10年工龄者为高发，最高点在1～5年工龄段。轻伤和重伤的年龄差别有统计学意义(Z=-2.184，P=0．029)，职业伤害程度与年龄呈正相关(r=0．041，P=0.011)。职业伤害主要分布在打眼、出矿、钳工、起重、支柱五大工种，易受伤部位是手、脚、头、四肢、五官，易受伤类型是物击、车辆、高坠。结论 某有色金属企业职业伤害发生率逐年下降，综合干预收到了效果，职业伤害是可以预防和控制的。     

Congenital malformations and death among the offspring of Danish pharmacy assistants

Congenital malformations, stillbirth, and infant mortality were studied in a cohort of all female pharmacy assistants in Denmark under the age of 40 years who were members of the national union in 1979 to 1984 (4,939). Data on all births and deaths during first year of life during the study period were identified through the national birth register. Information on type of work, exposures, and life-style variables were obtained by postal questionnaires, to which 93% responded. In general, pharmacy assistants had a low frequency of congenital malformation and death among their offspring. Compared with an internal reference group, pharmacy assistants engaged in production or packing of pharmaceutical products experienced an increased prevalence of congenital malformations among their offspring. Working with identification and controls showed a slightly increased risk of death during the first year of life of the children. This could indicate occupational risks, but other explanations cannot be excluded.     

父母MTHFR基因型与子代先天性心脏病的关系

目的　探讨父母双方 MTHFR基因型对子代发生先天性心脏病的影响。方法　采用病例对照研究方法 ,研究对象来自辽宁省十余个市县 ,收集其肘静脉血液 ,用 PCR- RFL P方法确定MTHFR基因型。结果　两组父、母亲单独比较其基因型构成、等位基因频率 ,其差异无显著性 ;父母各种基因型组合两两比较也无统计学意义。将父母的等位基因合在一起 ,则病例组的 T等位基因频率 (5 7.94 % )高于对照组 (5 1.0 3% ) ,P <0 .0 5 ,OR值 1.32 ;父母双方均是纯合突变会增加后代患 CHD的危险 ,χ2 =6 .2 6 ,P <0 .0 5 ,OR值为 4 .33(95 % CI :1.18～ 18.77) ;通过计算后代纯合突变的概率 ,发现后代纯合突变的概率越大 ,患 CHD的风险性越大。结论　父母双方 MTH-FR6 77TT基因型与后代 CHD的发生有关 ,后代 TT基因型是 CHD发生的危险因素之一     

A classification scheme for aggregating u.s. census occupation and industry codes

The use of occupation as a surrogate for workplace exposures when more specific information is unavailable is common yet is particularly challenging in studies involving many diverse occupations. A classification scheme that aggregates workers based on similar job tasks and potential exposures was developed for use in a Canadian study, and its adaptation for a similar U.S. study is described. The 56 occupational categories and 1980 U.S. census occupation and industry codes used to create each are presented. The scheme was developed using the distribution of occupations and industries in two limited study populations, and no exposure measurements were taken in its preparation. However, the aggregation of jobs with similar exposures has practical utility in the analysis of a large number of specific occupations, each with a small number of workers. As a result, the scheme presented can provide a starting point for researchers facing this task in the analysis of case-control occupational data.     

Esophageal cancer and occupation in a cohort of swedish men

Using the Cancer Environment Registry of Sweden, which links the 1960 census information on employment with cancer incidence data from 1961-1979, we conducted a systematic, population-based assessment of esophageal cancer incidence by industry and occupation for men in Sweden. A general reduction in esophageal cancer incidence was found among agricultural and professional workers, whereas excess incidence was found among business, sales, and some craftsmen and production jobs. Elevated incidence was associated with several specific industries, including the food (SIR = 1.3, p < 0.05), beverage and tobacco (SIR = 1.8, p < 0.05) industries, vulcanizing shops within the rubber industry (SIR = 4.7, p < 0.01), and certain automotive building industries. Incidence also was increased among brewery workers (SIR = 4.2, p < 0.01) and butchers (SIR = 2.1, p < 0.01), and among individuals with certain service jobs, particularly waiters in the hotel and restaurant industry (SIR = 3.1, p < 0.01). Some of the occupational associations may be explained by lifestyle factors such as alcohol drinking and smoking, whereas others are specific and tend to support those of earlier investigations. This study adds to the evidence of a small but possibly important role of occupation in esophageal cancer etiology.     

Mortality among rubber workers: X. Reclaim workers

This study evaluated the mortality experience of 1,352 white and 438 nonwhite men who worked in the rubber-reclaiming division of a large rubber manufacturing company. In comparisons of mortality of white reclaim workers with that of nonreclaim workers rate ratios were 2.7 for esophageal cancer (six observed deaths among reclaim workers), 2.1 for bladder cancer (seven observed deaths), and 4.5 for multiple myeloma (six observed deaths). The excess of bladder cancer among white reclaim workers may be associated with their employment in other high-risk areas of the plant, whereas no such explanation was found for the excesses of esophageal cancer and multiple myeloma. Overall, the lung cancer mortality rate of white reclaim workers was similar to the rate of US white males and other white rubber workers. There was a 50% excess of lung cancer deaths among nonwhite reclaim workers compared with other nonwhite rubber workers. However, this observation is based on small numbers, and no firm conclusions can be reached about the risk of lung cancer associated with reclaim operations in this group of rubber workers.     

Paternal Occupational Lead Exposure and Pregnancy Outcome

Abstract

Self-reported reproductive histories of male employees of a lead-zinc smelter were related to pre-conception measures of lead exposure to examine associations between paternal occupational lead exposure and adverse pregnancy outcome The participants reported 2,021 pregnancies which resulted in 1,684 normal live births, 12 stillbirths, 30, birth defects, 203 spontaneous abortions, and 92 “other” outcomes. Birth defects and stillbirths were combined for the analysis. The risk of a stillbirth or birth defect was elevated for pre-conception employment in a high-lead-exposure compared with a low-lead exposure job (odds ratio = 2.7, 95,% confidence interval = 0.7, 9.6). A similar risk was found for pre-conception blood lead levels of 25–39 μg/dL and ≥40μg/dL when compared With blood lead)level of <25μg/dL(OR = 2.9,95% CI = 0.6, 13.3 and OR = 2.5,95% CI = 0.5,11.6, respecdvely). No association was found between pre-conception lead exposure and spontaneous abortion. A relatively low response rate to the questiollnaire and potentially erroneous reporting of reproductive outcome by male workers are limitations of the study.     

Cardiovascular malformations and organic solvent exposure during pregnancy in Finland

In order to investigate the possible association between cardiovascular malformations and maternal exposure to organic solvents during the first trimester of pregnancy, 569 cases and 1,052 controls were retrospectively studied. The cases represented all infants with diagnosed cardiovascular malformations born in Finland in 1982-1984, and the controls were randomly selected from all normal births in the country during the same period. All mothers were interviewed approximately 3 months after delivery by a midwife using a structured questionnaire. Exposures to organic solvents at work during the first trimester of pregnancy were slightly more prevalent among the mothers of affected infants (10.4%) than among those of controls (7.8%). Logistic regression analysis of exposure to organic solvents showed an adjusted relative odds ratio of 1.3 (95% confidence interval, 0.8-2.2). In the analysis of ventricular septal defect, exposure to organic solvents showed an adjusted relative odds ratio of 1.5 (95% confidence interval, 1.0-3.7).     

Asthma mortality and occupation in Sweden 1981–1992

The objective of the present study was to investigate mortality attributable to asthma in different occupations. The mortality from asthma among Swedish workers between 1981 and 1992 was investigated by a linkage between official mortality statistics and the occupational information in the 1980 National Census. For each occupation, a smoking-adjusted standardized mortality ratio (SMR) was calculated. The information about smoking habits was obtained from smoking surveys carried out from 1977 to 1979. Only occupations with more than five cases were considered in the analysis. Significantly increased mortality from asthma was found among male farmers (smoking-adjusted SMR = 146; 95% confidence interval [CI] 105–187) and male professional drivers (smoking-adjusted SMR = 144, 95%CI = 101–209) and female hairdressers (smoking-adjusted SMR = 332, 95%CI = 102–525). The increased mortality among three occupational groups (hairdressers, farmers, and professional drivers) out of 46 groups analyzed may be random occurrences. However, farmers and hairdressers are exposed to agents causing asthma, indicating that the increased mortality may be attributable to occupational exposure. Am. J. Ind. Med. 31:678–681, 1997. © 1997 Wiley-Liss, Inc.     

Maternal exposure to ambient levels of benzene and neural tube defects among offspring: Texas, 1999-2004

Background

Previous studies have reported positive associations between maternal exposure to air pollutants and several adverse birth outcomes. However, there have been no studies assessing the association between environmental levels of hazardous air pollutants, such as benzene, and neural tube defects (NTDs), a common and serious group of congenital malformations.

Objective

Our goal was to conduct a case–control study assessing the association between ambient air levels of benzene, toluene, ethylbenzene, and xylene (BTEX) and the prevalence of NTDs among offspring.

Methods

The Texas Birth Defects Registry provided data on NTD cases (spina bifida and anencephaly) delivered between 1999 and 2004. The control group was a random sample of unaffected live births, frequency matched to cases on year of birth. Census tract–level estimates of annual BTEX levels were obtained from the U.S. Environmental Protection Agency 1999 Assessment System for Population Exposure Nationwide. Restricted cubic splines were used in mixed-effects logistic regression models to determine associations between each pollutant and NTD phenotype.

Results

Mothers living in census tracts with the highest benzene levels were more likely to have offspring with spina bifida than were women living in census tracts with the lowest levels (odds ratio = 2.30; 95% confidence interval, 1.22–4.33). No significant associations were observed between anencephaly and benzene or between any of the NTD phenotypes and toluene, ethylbenzene, or xylene.

Conclusion

In the first study to assess the relationship between environmental levels of BTEX and NTDs, we found an association between benzene and spina bifida. Our results contribute to the growing body of evidence regarding air pollutant exposure and adverse birth outcomes.     

A case-control study of multiple myeloma and occupation

Lifetime job histories from a population-based, case-control study were analyzed to investigate the relationship between multiple myeloma and employment in various occupations and industries. Interviews were obtained from 89% (692) of eligible incident cases and 83% (1683) of eligible controls. An elevated risk was observed among persons ever employed as painters [odds ratio (OR) + 2.1, 95% confidence interval (CI) + 1.2–3.6], particularly for those employed for 10 or more years (OR + 4.1, 95% CI + 1.8–10.4). A small excess risk was observed among agricultural workers employed for 10 or more years (OR + 1.3, 95% CI + 1.0–2.2), with a higher relative risk observed among farm laborers (OR + 1.8, 95% CI + 1.0–4.0). Among agricultural workers who reported having been highly exposed to pesticides, the OR was 5.2 (95% CI + 1.6–21.1). Some evidence, based on smaller numbers, was also found to support an association with firefighting and employment in the petroleum- and coal-products manufacturing industries. Little evidence was found to support the previously noted association with wood exposure, and no evidence for an association with employment in the rubber or petroleum refining industries was found. This study lends further support to previously reported associations between multiple myeloma and employment among painters and agricultural workers. © 1993 Wiley-Liss, Inc.     

Occupational hazards and pregnancy outcomes.

This study examined the association between exposure to occupational hazards and pregnancy outcomes using data from a case-control study conducted in 29 hospitals in Shanghai, China. The sample included 1,875 perinatal deaths and newborns with birth defects and the same number of controls. Information on mother's exposure to occupational radiation, chemicals, noise, and pesticides was investigated. Logistic regression analysis controlling for potential confounders showed that exposure to radiation before/during pregnancy was associated with antepartum fetal death, birth defects, small-for-gestational-age (SGA), and threatened abortion. Exposure to chemicals before/during pregnancy was associated with antepartum fetal death, early neonatal death, birth defects, preterm birth, and threatened abortion. Women exposed to pesticides during pregnancy had an increased risk of SGA and threatened abortion. Exposure to occupational noise during pregnancy increased the risk of antepartum fetal death. Furthermore, higher than expected numbers of congenital anomalies in the central nervous system (CNS) were identified among women exposed to chemicals before pregnancy and to pesticides during the first trimester of pregnancy. No significant association was found between occupational exposure and intrapartum fetal death. Although recall bias may be possible in our study, the findings encourage further research.     

Comparison of death certificate occupation and industry data with lifetime occupational histories obtained by interview: variations in the accuracy of death certificate entries

This study compares usual and recent occupation and industry data from lifetime work histories obtained by interview with death certificate entries for occupation and industry for 2,435 persons diagnosed with cancer. Match rates are calculated as the percent of death certificate occupation and industry entries that were confirmed by interview data and are compared for exact 3-digit 1980 U.S. Census Bureau occupation and industry codes and for groups of these codes. The overall match rate for individual usual occupation codes was 47.9% and for exact usual industry codes it was 61.8%. Significant differences between the interview data for usual occupation or industry and the death certificate entry were observed by race and gender, marital status, number of years worked, and occupation and industry groups and by age for industry. Misclassification or overreporting of occupation and industry data on the death certificate ranged from 30 to 50% in this study. Our results suggest that the utility of death certificate data for investigations into the occupational risk factors for cancer may be quite limited.     

The Risk of Birth Defects in Multiple Births: A Population-Based Study

Objectives: To determine if multiple births have higher risks of birth defects compared to singletons and to identify types of birth defects that occur more frequently in multiple births, controlling for seven sociodemographic and health-related variables. Methods: A retrospective cohort study was conducted of all resident live births in Florida during 1996–2000 using data from a population-based surveillance system. Birth defects were defined as in the 9th edition of the International Classification of Diseases—Clinical Modification (ICD-9-CM) code for the 42 reportable categories in the Centers for Disease Control and Prevention (CDC) Birth Defects Registry list and eight major birth defects classifications. Relative risks (RR) before and after adjusting for control variables and 95% confidence intervals (95% CI) were calculated. The control variables included mother's race, age, previous adverse pregnancy experience, education, Medicaid participation during pregnancy, infant's sex and number of siblings. Results: This study included 972,694 live births (27,727 multiple births and 944,967 singletons). Birth defects prevalence per 10,000 live births was 358.50 for multiple births and 250.54 for singletons. After adjusting for control variables, multiple births had a 46% increased risk of birth defects compared to singletons. Higher risks were found in 23 of 40 birth defects for multiple births. Five highest adjusted relative risks for birth defects among multiple births were: anencephalus, biliary atresia, hydrocephalus without spina bifida, pulmonary valve atresia and stenosis, and bladder exstrophy. Increased risks were also found in 6 out of 8 major birth defects classifications. Conclusions: Multiple births have increased risks of birth defects compared to singletons.