Health effects associated with exposure to anaesthetic gases in Ontario hospital personnel.

In a retrospective study (by questionnaire) of 8032 personnel exposed to anaesthetic gases in operating and recovery rooms in Ontario hospitals, and 2525 non-exposed hospital staff, the response was 78.8% for the exposed and 87.2% for the unexposed personnel during the period 1981-5. Logistic regression analysis, with age and smoking standardised, showed that women in the exposed group had significantly increased frequencies of spontaneous abortion and their children had significantly more congenital abnormalities (p less than 0.05). No chronic disease was significantly associated with the exposed group. These findings, together with similar ones from other studies, suggest that it is prudent to minimise exposure to waste anaesthetic gases.     

Health effects associated with exposure to anaesthetic gases in Ontario hospital personnel

In a retrospective study (by questionnaire) of 8032 personnel exposed to anaesthetic gases in operating and recovery rooms in Ontario hospitals, and 2525 non-exposed hospital staff, the response was 78.8% for the exposed and 87.2% for the unexposed personnel during the period 1981-5. Logistic regression analysis, with age and smoking standardised, showed that women in the exposed group had significantly increased frequencies of spontaneous abortion and their children had significantly more congenital abnormalities (p less than 0.05). No chronic disease was significantly associated with the exposed group. These findings, together with similar ones from other studies, suggest that it is prudent to minimise exposure to waste anaesthetic gases.     

Review of epidemiologic studies of paternal occupational exposure and spontaneous abortion

The question of whether paternal exposures influence risk of spontaneous abortion is of great public interest, with the possibility supported by laboratory investigations. Thirty-nine studies of male occupational exposure and risk of spontaneous abortion were examined, with the methods and results tabulated. Many of those reports were limited by exposure data based on maternal report of the father's job title or by potentially inaccurate paternal reports of spontaneous abortion, though the quality of more recent studies is markedly enhanced. Mercury has been implicated most strongly based on recent studies that included quantitative exposure estimates; a number of studies showing associations for exposure to anesthetic gases. Suggestive associations have also been found inconsistently for exposure to lead, rubber manufacturing, selected solvents, and some pesticides. Further study is encouraged, but with more intensive effort to measure accurately both spontaneous abortion and occupational exposures. © 1994 Wiley-Liss, Inc.     

Employment status as a confounder when assessing occupational exposures and spontaneous abortion

Studies of occupational exposure and spontaneous abortion may use pregnancies during which the mother was unemployed as part or all of the unexposed comparison group. Any type of maternal employment, however, may be a risk factor for spontaneous abortion, and potential confounder in occupational reproductive studies. This study evaluates the effect of employment in a cohort of pregnancies of 1535 women. Employed pregnancies had a significantly higher rate of spontaneous abortion (14.5%) than unemployed pregnancies (11.7%) (RR = 1.23, 95% CI = 1.02, 1.49). Gravidity acted as an effect modifier, as the employment effect was seen only in multigravidous pregnancies (RR = 1.38, 95% CI = 1.11, 1.72) and not primigravidous pregnancies (RR = 0.96). The effect persisted when an independent sample of one randomly selected pregnancy per woman was used for the analysis (RR = 1.27, 95% CI = 0.90, 1.79). The data were examined for confounding by other factors which could explain the excess in spontaneous abortion among employed pregnancies. The employment effect persisted with adjustment for other risk factors including maternal age, education, income, maternal diabetes, race, alcohol usage and smoking, and prior pregnancy ending in induced abortion. Stratifying by prior pregnancy loss eliminated the employment effect among those with prior loss (RR = 1.03) but enhanced the effect among those multigravidous without the risk factor (RR = 1.50, 95% CI = 1.15, 1.97). Selection bias, also, was explored as a possible explanation of this employment effect, but could not be substantiated. Assessment of a true exposure effect requires consideration of a potential employment effect either in the design or analysis.     

Spontaneous abortion in spouses of greenhouse workers exposed to pesticides

Objective The aim of this study was to explore the association between exposure to specific pesticides (including endocrine disrupters) of greenhouse workers and spontaneous abortion in their spouses. Methods A group of exposed workers was compared with a non-exposed group. The risk of spontaneous abortion was evaluated using a logistic regression model. Results A significantly higher rate of spontaneous abortion was observed among spouses of workers exposed to specific compounds (atrazine, benomyl-carbendazim, carbaryl and DDT) in comparison with spouses of the unexposed group. The logistic regression model confirmed the increased risk of spontaneous abortion (OR=11.8; 95% CI 2.3–59.6). Conclusions These findings suggest that occupational exposure to pesticides might have an adverse effect on the partner’s reproductive health.     

Pregnancy outcome following maternal organic solvent exposure: A meta-analysis of epidemiologic studies

Background Evidence of fetal damage or demise from occupational organic solvent levels that are not toxic to the pregnant woman is inconsistent in the medical literature. The risk for major malformations and spontaneous abortion from maternal inhalation of organic solvent exposure during pregnancy was summarized using meta-analysis. Methods Medline, Toxline, and Dissertation Abstracts databases were searched to locate all research papers published in any language from 1966 to 1994. Included were studies that were case-control or cohort in design and indicated first trimester (or up to 20 weeks gestation for spontaneous abortion) maternal solvent exposure. A summary odds ratio (ORs) with 95% confidence intervals (CI) was calculated from research results combined by the Mantel-Haenszel method. Results In total, 559 studies were obtained from the literature search. Five studies for each outcome of interest qualified for inclusion in the analysis. The ORs for major malformations from five studies (n = 7,036 patients) was 1.64 (CI 1.16–2.30) and for spontaneous abortion from five studies (n = 2,899 patients) was 1.25 (CI 0.99–1.58). Conclusions Maternal occupational exposure to organic solvents is associated with a tendency toward an increased risk for spontaneous abortion and additional studies may affect the trend. There is a statistically significant association with major malformations which warrants further investigation. Am. J. Ind. Med. 34:288–292, 1998. © 1998 Wiley-Liss, Inc.     

Effects of paternal occupational exposure on spontaneous abortions.

BACKGROUND: Paternal exposure to mutagenic agents has been suggested to affect pregnancy outcome adversely. METHODS: A nationwide data base of medically diagnosed spontaneous abortions and other pregnancies and national census data was used to evaluate the effects of men's occupational exposures on risk of spontaneous abortion in 99,186 pregnancies in Finland. Census data from the years 1975 and 1980 provided information about the occupation, industry, and socioeconomic status. A job-exposure classification was developed to classify women and their husbands according to possible occupational exposures on the basis of their occupational title and industry. RESULTS: In 10% of the pregnancies, the husband was exposed to one or more of the mutagens, and the rate of spontaneous abortion was unaffected (OR = 1.0). Of the 25 specific mutagenic exposures evaluated, paternal exposure to four (ethylene oxide, rubber chemicals, solvents used in refineries, and solvents used in the manufacturing of rubber products) was associated with an increased relative risk of spontaneous abortion. In addition, the risk of spontaneous abortion was higher among wives of rubber products workers than among unexposed men. CONCLUSIONS: Although there is some biological rationale for the findings of this study, these findings need to be confirmed by studies in which individual exposures can be measured directly.     

Persistent cognitive functioning deficits in operating rooms: two cases

BACKGROUND: To date, chronic toxic encephalopathy (CTE) has never been described in operating room personnel. CASE REPORT: We report two cases of anaesthetists who developed this pathology. They have both used anaesthetic gases for many years in paediatric surgery. Air conditioning was deficient during three years in operating rooms and atmospheric anaesthetics concentration was high (N(2)O mean concentration: 311 ppm, peak levels 1,600 ppm; halogenated: 16 ppm, peak levels: 1,600 ppm). CLINICAL SYMPTOMS: Mood troubles and non-specific neuropsychic deficits gradually evolved until they had to stop working. Neuropsychological assessment showed important deficits in attention, executive functioning, short-term memory and visuo-spatial organization. Blood tests, VEPs, MRI, neuroSPECT and cardiovascular exams were normal. Troubles had slowly improved after cessation of exposure and sequels still remain. CONCLUSION: These CTE cases seem to be the consequence of a long-term exposure to important levels of anaesthetic gases, and particularly nitrous oxide. It points out the importance of preventive measures in operating rooms, where occupational hazards are varied.     

Association of petrochemical exposure with spontaneous abortion

OBJECTIVES: To assess the association between petrochemical exposure and spontaneous abortion, a retrospective epidemiological study in a large petrochemical complex in Beijing, China was conducted. METHODS: Plant employment records identified 3105 women who were married, were 20-44 years of age, and had never smoked. Of those, 3070 women (98.8%) reported at least one pregnancy. From this group, 2853 (93%) of the women participated in the study. According to their plant employment record, about 57% of these women workers reported occupational exposure to petrochemicals during the first trimester of their pregnancy. Trained interviewers administered a standardised questionnaire to this group of women and their husbands, collecting information on reproductive history, pregnancy outcomes, employment history, occupational exposure, smoking habits, alcohol consumption, indoor air pollution, and demographic variables. The results from the womens' first pregnancies were analysed. RESULTS: There was a significantly increased risk of spontaneous abortion for women working in all of the production plants with frequent exposure to petrochemicals (8.8%; range of 5.8%-9.8%) compared with those working in nonchemical plants (2.2%; range of 0.0%-7.1%). Also, when a comparison was made between exposed and non-exposed groups within each plant, exposure to petrochemicals was consistently associated with an increased risk of spontaneous abortion. The overall odds ratio (OR) was 2.7 (95% confidence interval (95% CI) 1.8 to 3.9) after adjusting for potential confounders. When the analysis was performed with the exposure information obtained from the women' interview responses for (self reported) exposures, the estimated OR for spontaneous abortions was 2.9 (95% CI 2.0 to 4.0). The analysis was repeated by excluding those 452 women who provided inconsistent reports between recalled exposure and work history, and a comparable risk of spontaneous abortion (OR 2.9; 95% CI 2.0 to 4.4) was found. In analyses for exposure to specific chemicals, an increased risk of spontaneous abortion was found with exposure to most chemicals, and the results for benzene (OR 2.5; 95% CI 1.7 to 3.7), gasoline (OR 1.8; 95% CI 1.1 to 2.9), and hydrogen sulphide (OR 2.3; 95% CI 1.2 to 4.4) were significant. CONCLUSION: An increased risk of spontaneous abortion was found associated with the exposure to petrochemicals, including benzene, gasoline, and hydrogen sulphide.

 

     

Spontaneous abortion and maternal work in greenhouses

BACKGROUND: A positive association between maternal occupational exposure to pesticide and spontaneous abortion has been reported in some studies. Work in greenhouses may imply exposure of pregnant women to pesticides continuously and at elevated level. METHODS: A total of 717 women working in greenhouses provided information on 973 pregnancies, including 110 spontaneous abortions. These pregnancies were classified as exposed or not exposed according to maternal occupation, re-entry activities and application of pesticides in greenhouses during at least 1 month in the first trimester of pregnancy. The ORs for spontaneous abortion were estimated through a generalised estimate equations model for all orders of pregnancy together, and through a logistic regression model limited to first pregnancies. RESULTS: Increased risks of spontaneous abortion were found for maternal re-entry activities within 24 hr after pesticides were applied (all orders of pregnancy: OR 3.2, 95% CI 1.3-7.7; first pregnancies: OR 3.8, 95% CI 1.0-13.9) and for those who applied pesticides (all orders of pregnancy: OR 2.6, 95% CI 1.0-6.6; first pregnancies: OR 3.7, 95% CI 0.7-20,6) CONCLUSIONS: The observed results support the hypothesis of an association between maternal work in greenhouses and spontaneous abortion. The main limitations of the study are lack of information on the specific chemicals used and the small number of pregnancies heavily exposed to pesticides.     

Shift work, nitrous oxide exposure, and spontaneous abortion among Swedish midwives.

OBJECTIVES: To study the relation between irregular work hours, nitrous oxide (N2O) exposure, and the risk of spontaneous abortion. METHODS: All 3985 female members of the Swedish Midwives Association in 1989, born in 1940 or later, received a questionnaire on exposure before and during all of their pregnancies. Questions on work conditions covered occupation, extent of employment, workplace, work schedules, use of anaesthetics, and work load. The association between exposure variables and spontaneous abortion was analysed by logistic regression models. RESULTS: Night work and three shift schedules among midwives showed increased odds ratios (ORs) (95% confidence intervals (95% CI)) 1.63 (0.95-2.81) and 1.49 (0.86-2.59), respectively. The ORs of late spontaneous abortions (after the 12th week of pregnancy) was increased for night work 3.33 (1.13-9.87). Use of N2O (> 50% of the deliveries) was not associated with increased risk of spontaneous abortion OR 0.95 (0.62-1.47). Frequent or permanent shortage of staff was related to an increased risk of spontaneous abortions before the 13th week of pregnancy. CONCLUSIONS: The results support the hypothesis that night work and high work load increase the risk of spontaneous abortion.     

Occupational exposure to antineoplastic agents: self-reported miscarriages and stillbirths among nurses and pharmacists.

Insult to the germ cells of an ovum or sperm prior to pregnancy as well as exposures to a fetus during pregnancy can affect the outcome of a pregnancy. Antineoplastic agents are mutagenic and teratogenic, so the potential effects of exposure on reproduction are of concern to the workers who handle them. This study investigates pregnancy loss associated with occupational exposures to antineoplastic drugs by comparing rates of spontaneous abortion and stillbirths for pregnancies without antineoplastic exposure and exposed pregnancies in which the pregnant woman or the father handled antineoplastic agents either before or during the pregnancy. A total of 7094 pregnancies of 2976 pharmacy and nursing staff were examined. After age during pregnancy, prior gravidity, maternal smoking during the pregnancy, and occurrence of a spontaneous abortion or stillbirth in a prior pregnancy were controlled for, exposure of the mother to or the handling of antineoplastic agents during the pregnancy was associated with a significantly increased risk of spontaneous abortion (odds ratio = 1.5; 95% confidence interval, 1.2 to 1.8) and combined risk of spontaneous abortion and stillbirth (odds ratio = 1.4; 95% confidence interval, 1.2 to 1.7) but not stillbirth alone. Among the wives of exposed men, too few stillbirths occurred to allow analysis. However, for spontaneous abortion and any loss, the patterns of increased risk were similar to those seen for women, although the odds ratios were not statistically significant.     

Spontaneous abortions and malformations in the offspring of nurses exposed to anaesthetic gases, cytostatic drugs, and other potential hazards in hospitals, based on registered information of outcome.

Nurses working in selected departments of general hospitals in Finland were collected from a central register on health personnel in Finland. Using the Hospital Discharge Register and the Register of Congenital Malformations, case nurses were selected who had had a spontaneous abortion (N = 217) or a malformed child (N = 46) between the years 1973 and 1979. Controls consisted of three nurses who had had a normal birth; the control nurses were matched for age and hospital of employment. Information on exposure in the first trimester of pregnancy was sought through the head nurses of the hospitals. No significant increase in risk of spontaneous abortion or of malformation was observed after exposure to anaesthetic gases (odds ratio for spontaneous abortion 1.2), sterilising gases and soaps, or x-rays. Handling of cytostatic drugs did not affect the frequency of spontaneous abortion but was associated with malformations in the offspring. The odds ratio, based on eight cases, was 4.7 (p = 0.02) when the logistic model was adopted. The results suggest that the exposures investigated, other than cytostatic drugs, do not cause a strong reproductive risk. Further studies are needed, particularly on cytostatic drugs.     

Adenocarcinoma of the stomach and exposure to occupational dust

The authors studied 1,342 cases of adenocarcinoma of the stomach identified by a population-based cancer registry in Los Angeles County, California. The cases were males aged 20-64 years first diagnosed between 1972 and 1982. To determine whether exposure to occupational dust increased the risk of developing stomach cancer, occupational titles were rated for the likelihood of exposure to various kinds of dust. Men who worked in dusty jobs had a risk for developing stomach cancer 1.3 times that of unexposed men (95% confidence interval = 1.2-1.4). The association of exposure to dust with stomach cancer was stronger at higher levels of exposure. The risk was not uniform throughout the stomach: the highest risk (1.8 times that of unexposed men) was found for the antrum/pylorus. At that site, exposure to mineral dust carried the greatest risk for cancer (3.7 times the risk for unexposed men). The highest risks from dust exposure were observed in blacks. Risk was related to race, socioeconomic status, and immigrant status, but these factors did not entirely explain the association with dust exposure. The observed relation between dust exposure and stomach cancer is consistent with results of previous mortality and case-control studies of cancer in men who worked in dusty occupations. Ingested dust may be one factor in the etiology of adenocarcinoma of the stomach.     

尿道下裂危险因素的病例对照研究

目的 探讨尿道下裂病因。方法 采用以医院为基础的1:2配比的病例对照研究方法,以统一的调查表及调查方式对107倒尿道下裂及214例对照进行面对面问卷调查,应用SAS 6.12软件对所有调查因素进行单因素及多因素logistic回归分析。结果 胎儿尿道下裂的发生与母亲孕前自然流产史(OR=3.87,95％CI:1.60～9.39)、孕期发生先兆流产(OR=3.57,95％CI:1.31～9.64)、孕早期感冒伴发热(OR=7.63,95％CI:2.50～23.24)、孕中期用抗感染和/或解热止痛药(OR=16.46,95％CI;3.46～78.21)、父亲职业性接触农药(OR=3.70,95％CI:1.49～9.16)及胎儿低出生体重(OR=12.62,95％CI:2.97～53.67)呈正相关,与母亲孕早期增加蛋白质类营养(OR=0.33,95％CI:O.15～0.74)呈负相关。结论 母亲孕前自然流产史、孕期发生先兆流产、孕早期感冒伴发热、孕中期用抗感染和/或解热止痛药、父亲职业性接触农药、胎儿低出生体重等可能增加胎儿发生尿道下裂的危险,而母亲孕早期增加蛋白质类营养可能降低胎儿发生尿道下裂的危险。     

Spontaneous abortions among veterinarians

OBJECTIVES: The objective of the study was to determine whether female veterinarians have an increased risk of spontaneous abortion and whether the potential risk is related to the type of work veterinarians do. METHODS: The investigation was a retrospective cohort study among all the female members of the Finnish Veterinary Association (N=549). Information on pregnancies was obtained from hospital records from 1973-1990. The risk of spontaneous abortion among the veterinarians was compared with that of all other Finnish women and other upper-level employees. Odds ratios from logistic regression analyses were used as the estimates of the risk ratios. RESULTS: The risk of spontaneous abortion was 10.5% for the veterinarians. In the 1970s, practicing veterinarians had an increased risk of spontaneous abortion as compared with other Finnish women (adjusted odds ratio 1.8, 95% confidence interval 1.0-3.1) or other upper-level employees (adjusted odds ratio 2.0, 95% confidence interval 1.1-3.4). In the 1980s, the risk fell below that of other Finnish women. No essential differences were observed in the risk between the veterinarians employed in different occupational categories. CONCLUSIONS: The results suggest that the veterinarians had an increased risk of spontaneous abortion in the 1970s, but not in the 1980s. Factors which might have contributed to this decrease in risk include decreases in the prevalence and level of exposure to harmful agents, improvements in the occupational hygiene of the work environment, and an increased awareness of reproductive hazards and the use of sick leave during pregnancy.     

Adverse pregnancy outcomes in relation to water consumption: a re-analysis of data from the original Santa Clara County Study, California, 1980-1981.

Residents of a census tract that received drinking water from a well contaminated with solvents were previously shown to experience a spontaneous abortion rate over twice that occurring in an unexposed census tract. In addition, the rate of birth defects in the exposed tract was three times that in the unexposed tract. Surprisingly, increased tapwater consumption was associated with higher rates of spontaneous abortions in both the exposed and the unexposed tracts. Subsequent studies in this area have investigated the relation between spontaneous abortions and consumption of tapwater in more detail. In this report, data from the original study have been re-analyzed using methods comparable with those used in more recent studies. These results confirm the association between spontaneous abortions and reported cold tapwater consumption that was seen in the original study. The observed effect was not due to maternal risk factors, nor was it a function of consumption of bottled water. After controlling for bottled water, the odds ratio for consumption of tapwater was 3.4 (95% confidence interval = 0.6-19.4).     

Parental occupational exposure and spontaneous abortions in Finland

Spontaneous abortions were analyzed by the occupational exposure of women and their husbands, with data from the Finnish hospital discharge register and the national census. The occupations were grouped according to presumed exposure into seven categories: exposure to solvents; automobile exhaust fumes; polycyclic aromatic hydrocarbons; other chemicals; metals; textile dust; and animal microorganisms. The relative risks of spontaneous abortion were estimated with logistic regression analysis to adjust for potentially confounding factors. The broad exposure categories appeared, at most, to be weak risk factors of spontaneous abortion, because the relative risks of abortion were not significantly increased in any of the parental exposure groups. The analysis of detailed occupational categories showed some female and male occupations with an increased risk. The observations of increased risk related to laboratory work support earlier findings. The high number of textile occupations with increased risk is also worth noting, and further investigations are necessary to confirm whether this is due to occupational hazards or other factors.     

Interactive Effects of Maternal Vitamin D Status and Socio-Economic Status on the Risk of Spontaneous Abortion: Evidence from Henan Province,China

Background: Maternal vitamin D deficiency might generate adverse reproductive outcomes, and socio-economic inequalities in micronutrient-related diseases have often been found. This study aimed to explore the interactive effects of maternal vitamin D status and socio-economic status (SES) on risk of spontaneous abortion. Methods: A population-based case–control study was conducted including 293 women with spontaneous abortion and 498 control women in December 2009 and January, 2010 in Henan Province, China. Information on pregnancy outcomes, maternal demographic, lifestyle and exposure factors and blood samples were collected at the same time. Vitamin D deficiency was defined as 25(OH)D < 20 ng/mL. SES index was constructed with principal component analysis by aggregating women’s and their husbands’ education level and occupation, and household income and expenditure. Interactive effects were assessed on a multiplicative scale with ratio of the odds ratio (ROR). Results: Compared to those with high SES and vitamin D sufficiency, women with vitamin D deficiency and low SES index had an increased risk of spontaneous abortion (aOR: 1.99; 95% CI: 1.23–3.23). The ROR was 2.06 (95% CI: 1.04–4.10), indicating a significant positive multiplicative interaction. Conclusions: Maternal low SES may strengthen the effect of vitamin D deficiency exposure on spontaneous abortion risk in this Chinese population.