Risk of spontaneous abortion among women exposed to polybrominated biphenyls

Accidental contamination of livestock in Michigan in 1973 with polybrominated biphenyls (PBBs) led to the establishment of a registry of exposed individuals in 1976. At the time of enrollment, serum was collected and analyzed for PBBs and polychlorinated biphenyls (PCBs). In 1997, women aged 18 years or older and active in the registry were invited to participate in a telephone interview about their health. Using generalized estimating equations to account for correlated outcomes within the same woman, we assessed the risk of spontaneous abortion among 529 women with 1344 potentially exposed pregnancies. PBB and PCB exposure were not associated with risk of spontaneous abortion after adjusting for maternal age at conception, age at menarche, and prior infertility. Compared to pregnancies with PBB exposure below the limit of detection, those with levels above 2.9 ppb had a non-significant reduced odds of spontaneous abortion (adjusted OR=0.73; 95% CI=0.47-1.13). Compared to pregnancies with PCB exposure below the limit of detection, those with levels above 6.5 ppb had little difference in risk (adjusted OR=0.91; 95% CI=0.59-1.41). Maternal age at conception above 34 years was significantly associated with elevated risk of spontaneous abortion (OR=2.46; 95% CI=1.10-5.49). The effect of prior infertility was of borderline significance (OR=1.52; 95% CI=0.98-2.38). Older age at menarche was associated with decreased risk of spontaneous abortion (adjusted OR=0.58; 95% CI: 0.38-0.89, comparing menarche at 12-13 with menarche <12). Our results do not support an association between exposure to PBBs or PCBs and 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.     

Relations of gestational length and timing and type of incomplete pregnancy to ovarian cancer risk

While the protective nature of parity with respect to ovarian cancer has been well documented, whether a history of incomplete pregnancy affects ovarian cancer risk is uncertain. Data collected from 739 epithelial ovarian cancer cases and 1,313 community controls in the Delaware Valley from 1994 to 1998 were used to evaluate the relation between gestational length and timing of first induced or spontaneous abortion and ovarian cancer risk. Incomplete pregnancy was not associated with ovarian cancer among nulliparous women or among ever-pregnant women either before or after adjustment for relevant confounders (for nulliparous women, odds ratio (OR) = 1.12, 95% confidence interval (CI): 0.66, 1.89; for ever-pregnant women, OR = 0.95, 95% CI: 0.76, 1.18). Among unigravid women, one full-term pregnancy was more protective than an incomplete pregnancy (adjusted OR = 0.29, 95% CI: 0.15, 0.57). These results were independent of the type of pregnancy loss. Among ever-pregnant women, a spontaneous abortion before a first birth provided significant protection (adjusted OR = 0.47, 95% CI: 0.30, 0.75), while no significant effect was found for an induced abortion prior to a first birth (adjusted OR = 0.80, 95% CI: 0.44, 1.47). These data do not support an independent association between incomplete pregnancies, either spontaneous or induced, and ovarian cancer risk.     

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.     

Prior spontaneous abortion, prior elective termination, interpregnancy interval, and risk of neural tube defects

A woman with a history of spontaneous abortion in her immediately prior pregnancy may be at increased risk for a pregnancy affected by a neural tube defect (NTD). A short interpregnancy interval may further increase this risk. Using data from a population-based case-control study (1989-1991), the authors investigated NTD risk resulting from a prior spontaneous abortion or elective termination and a short interpregnancy interval. Of 538 interviewed case mothers and 539 interviewed control mothers, 408 case mothers and 433 control mothers reported having a prior pregnancy. Analysis showed a slightly decreased NTD risk among mothers whose immediately prior pregnancy had ended in a spontaneous abortion or elective termination in comparison with a live birth (odds ratio (OR) = 0.82; 95% confidence interval (CI): 0.61, 1.1). This decreased risk was consistent across strata of short or long interpregnancy intervals. Additional analysis revealed an increased NTD risk for mothers with an interpregnancy interval of < or =6 months compared with >12-< or =24 months (OR = 1.5; 95% CI: 0.93, 2.4). This latter risk was greatest among mothers whose immediately prior pregnancy had resulted in a live birth (OR = 2.0; 95% CI: 1.0, 3.8) rather than a spontaneous abortion or elective termination (OR = 0.96; 95% CI: 0.44, 2.1). Adjustment for potential covariates did not substantially alter observed risk estimates.     

Work schedule during pregnancy and spontaneous abortion

BACKGROUND: There is inconsistent evidence as to whether work schedule (including rotating shifts and night work) can affect reproductive outcomes. METHODS: We investigated the association between work schedule and risk of spontaneous abortion in U.S. nurses. The Nurses' Health Study II is a prospective cohort study established in 1989. In 2001, information about occupational activities and exposures during pregnancy was collected from female nurses for the most recent pregnancy since 1993. Of 11,178 eligible respondents, 9547 (85%) indicated willingness to participate in the occupational study, and 8461 of those (89%) returned the questionnaire, for an overall participation rate of 76%. Of these, 7688 women had pregnancies that were eligible for analysis. RESULTS: Participants reported 6902 live births and 786 (10%) spontaneous abortions. Compared with women who reported usually working "days only" during their first trimester, women who reported usually working "nights only" had a 60% increased risk of spontaneous abortion (RR = 1.6; 95% confidence interval [CI] = 1.3-1.9). A rotating schedule, with or without night shifts, was not associated with an increase in risk (RR = 1.2 [CI = 0.9-1.5] and 1.0 [CI = 0.8-1.2], respectively). Women who reported working more than 40 hours per week during the first trimester were also at increased risk of spontaneous abortion (1.5; 1.3-1.7) compared with women working 21-40 hours, even after adjustment for work schedule. CONCLUSIONS: Nightwork and long work hours may be associated with an increased risk of spontaneous abortion. Further studies are needed to determine whether hormonal disturbances attributed to night work affect pregnancy outcome.     

Work with visual display units in pregnancy.

Data from the Montreal survey on occupational factors in pregnancy were used to test the hypothesis that visual display units (VDUs) constitute a hazard to reproduction. Use of a VDU was recorded in 4712 current and 2164 previous pregnancies of women in full time employment at time of conception. After allowance for seven confounding variables, the risk of spontaneous abortion in current pregnancies relative to all working women was 1.19 (90% CI 1.09-1.30) and in previous pregnancies, 0.97. In an analysis by occupational title, in which 60 occupational groups were aggregated into eight categories according to use of VDUs, the relative risk for spontaneous abortion was 1.06 (90% CI 0.8-1.4) in current pregnancies and 1.01 (90% CI 0.7-1.3) in previous pregnancies. This suggests that the small excess of spontaneous abortions among individual women reporting the use of VDUs in current pregnancies may have been due to recall bias. Relative risks for stillbirth, preterm birth, and low birth weight all had 90% confidence limits which included unity. In an analysis of congenital defects the number of pregnancies was increased to include women who worked 15 or more hours a week. In all but one of nine groups of congenital defect examined confidence limits for the relative risk included unity in both current and previous pregnancies. The relative risks for the renal urinary group of defects were raised in both current (1.84, 90% CI 1.07-3.15) and previous pregnancies (1.66, 90% CI 0.82-3.25). There being no prior reason to suspect a causal link with this type of defect, interpretation remains open to question.     

Work with visual display units in pregnancy

Data from the Montreal survey on occupational factors in pregnancy were used to test the hypothesis that visual display units (VDUs) constitute a hazard to reproduction. Use of a VDU was recorded in 4712 current and 2164 previous pregnancies of women in full time employment at time of conception. After allowance for seven confounding variables, the risk of spontaneous abortion in current pregnancies relative to all working women was 1.19 (90% CI 1.09-1.30) and in previous pregnancies, 0.97. In an analysis by occupational title, in which 60 occupational groups were aggregated into eight categories according to use of VDUs, the relative risk for spontaneous abortion was 1.06 (90% CI 0.8-1.4) in current pregnancies and 1.01 (90% CI 0.7-1.3) in previous pregnancies. This suggests that the small excess of spontaneous abortions among individual women reporting the use of VDUs in current pregnancies may have been due to recall bias. Relative risks for stillbirth, preterm birth, and low birth weight all had 90% confidence limits which included unity. In an analysis of congenital defects the number of pregnancies was increased to include women who worked 15 or more hours a week. In all but one of nine groups of congenital defect examined confidence limits for the relative risk included unity in both current and previous pregnancies. The relative risks for the renal urinary group of defects were raised in both current (1.84, 90% CI 1.07-3.15) and previous pregnancies (1.66, 90% CI 0.82-3.25). There being no prior reason to suspect a causal link with this type of defect, interpretation remains open to question.     

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.

 

     

Low birth weight in relation to multiple induced abortions.

BACKGROUND. Most studies report that a single induced abortion does not increase risk for delivering a low birth weight infant in a subsequent pregnancy. However, the effect of multiple abortions has not been adequately evaluated. METHODS. This relationship was studied in 6541 White women who delivered their first child between 1984 and 1987. We compared the frequencies of low birth weight (less than 2500 g) among infants born to 1999 women without prior induced abortion and 1999 women with one abortion with the frequencies of low birth weight among infants born to women with two (n = 1850), three (n = 520), and four or more (n = 173) prior induced abortions. RESULTS. After adjustment for confounding variables, we found no linear relationship in risk of low birth weight among women with one (relative risk [RR] = 1.2, 95% confidence interval [CI] = 0.9-1.5), two (RR = 1.5, 95% CI = 1.1-2.0), three (RR = 1.3, 95% CI = 0.8-1.9), or four or more (RR = 1.6, 95% CI = 0.9-2.9) prior induced abortions. CONCLUSIONS. These findings confirm earlier reports of little or no evidence of harmful effects on birth weight by one or by two or more induced abortions. We further report that risk is not significantly elevated even in women with three, four, or more prior terminations of pregnancy when compared with women with one or two abortions.     

Tobacco smoke exposure and pregnancy outcome among working women. A prospective study at prenatal care centers in Orebro County, Sweden

Among 4,687 women undergoing prenatal care in Orebro County, Sweden, from October 1980 to June 1983, 678 nonsmokers reported passive exposure to tobacco smoke. Of these women, 267 had been passively exposed at work, and the risk ratio (RR) for intrauterine death (spontaneous abortion or stillbirth) among these pregnancies was increased to 1.53 (95% confidence interval (CI) 0.98-2.38) compared with pregnancies of unexposed working women. This could not be explained by age, previous spontaneous abortion, educational level, planning of pregnancy, or alcohol use. The effect was confined to first-trimester fetal loss (adjusted RR = 2.16, 95% CI 1.23-3.81), while active smoking was associated with intrauterine death after the first trimester. Passive exposure in the workplace was weakly associated with preterm birth (less than 37 weeks) but not with low birth weight (less than 2,500 g) among full-term livebirths. Active smoking clearly increased the risk of both of these outcomes. However, passive exposure in the home only did not seem to affect pregnancy outcome. The lack of quantitative exposure data points to the need for more research before passive exposure to tobacco smoke can be regarded as an established hazard to fetal development and survival.     

Historical cohort investigation of spontaneous abortion in the semiconductor health study: Epidemiologic methods and analyses of risk in fabrication overall and in fabrication work groups

The risk of spontaneous abortion (SAB) in the semiconductor industry was examined in a historical cohort study of pregnancies at 14 companies. We identified Female employees who had worked for at least 6 months and whose ages ranged from 18 to 44 years during the 1986–1989 study period. Using company records, we included all fabrication-room (fab) employees and an Approximately equal number of nonfabrication (non-fab) employees, for a total sample of 7,269. Telephone interviews with 6,088 women (84%) identified 904 eligible pregnancies and 113 SABs. Exposure classification was based on questionnaire and industrial hygiene assessments of tasks the women performed during the first trimester of pregnancy. Using logistic regression to control for age, smoking, ethnicity, education, income, year of pregnancy, and stress, we found a higher risk of SAB in fab employees than in nonfab employees (15.0% of fab pregnancies ended in SAB vs. 10.4% of nonfab pregnancies, adjusted relative risk [RR] = 1.43, 95% CI = 0.95-2.09). Analysis of fab work groups showed that the highest relative risk was in MAsking employees (17.5% SAB rate, adjusted RR = 1.78, 95% CI = 1.17-2.62 in comparison with nonfab employees). Within MAsking, the highest risk was found in etching-related process employees (22.2% SAB rate, adjusted RR = 2.08, 95% CI = 1.27-3.19 in comparison to nonfab employees)     

A case-control study to investigate the role of recent spontaneous abortion in the aetiology of neural tube defects

Summary. Clarke et al.¹ suggested that women who have had a spontaneous abortion are at an increased risk in their next pregnancy of producing an offspring with a neural tube defect (NTD). A matched case-control study was carried out to test the related hypothesis that a spontaneous abortion occurring in the 6-month period prior to the conception of a pregnancy (recent spontaneous abortion) is a risk factor for the development of an NTD in that pregnancy. The cases were 177 singleton pregnancies to non-primigravida Leicestershire women, which were affected by non-syndromal NTDs between 1976 and 1989. Two control pregnancies were matched with each case on intended place of delivery and date of maternal last normal menstrual period (LNMP). After adjusting for potential confounders, recent spontaneous abortion was found to be associated with a decreased relative risk of neural tube defect, odds ratio 0.46, 95% confidence interval 0.20, 1.07. The result provided little evidence in favour of the hypothesis, suggesting instead that prior spontaneous abortion has a protective effect in relation to subsequent NTD development rather than being a major risk factor in the aetiology of NTDs.     

Spontaneous abortions among Finnish flight attendants.

We conducted a retrospective cohort study to investigate whether work as a cabin attendant is related to an increased risk for spontaneous abortion. Data on female cabin crew members were linked to medical records on pregnancies. There were 1751 eligible pregnancies for the final analysis. Flight attendants who worked during early pregnancy had a slightly elevated risk of spontaneous abortion, as compared with attendants who were pregnant outside a time span of active flying (odds ratio [OR] = 1.3; 95% confidence interval [CI], 0.9 to 1.8). During the earliest years of the study period (1973 through 1977), the risk seemed to be decreased (OR = 0.4; 95% CI, 0.2 to 1.1), whereas during the later years (1978 through 1994) the risk was increased (OR = 1.6; 95% CI, 1.1 to 2.4). The results are in agreement with earlier studies, showing suggestive evidence of a slightly increased risk of spontaneous abortion among female cabin crew members.     

Low birth weight in pregnancies following induced abortion: no evidence for an association

Compared with women delivering a first pregnancy, those delivering a second pregnancy after aborting the first have similar rates of low (less than 2,500 g) birth weight newborns (relative risk (RR) G2A1/G1 = 0.86, 95% confidence interval (CI) = 0.49-1.51) and mean birth weight (delta = 16.3 g, p = 0.63). Abortion of the first pregnancy prevents the reduction in low birth weight and increase in mean birth weight in the second pregnancy which delivery of the first pregnancy normally bestows (RR G2P1/G2A1 = 0.48, 95% CI = 0.25-0.90; delta = 135.3 g, p less than 0.0001). Two prior induced abortions do not significantly increase risk for low birth weight (RR G3A2/G1 = 1.14, 95% CI = 0.37-3.56) or decrease mean birth weight (delta = 29.0 g), compared with women delivering their first pregnancy. The second of two deliveries has a reduced risk of low birth weight irrespective of whether both deliveries follow an aborted first pregnancy. Adjustment for confounding factors did not materially change these results. Low birth weight rates were higher after abortions performed in hospital compared with elsewhere (p = 0.03), but mean birth weight was not affected. Gestation at abortion, vacuum aspiration or dilatation and curettage, and abortion complications were unrelated to birth weight of subsequent pregnancies. Pregnancies conceived within six months of a prior abortion or delivery had lower birth weight than if the antecedent pregnancy ended more than six months previously.     

Prospective monitoring of early fetal loss and clinical spontaneous abortion among female semiconductor workers

Women who work in silicon wafer fabrication rooms (fabs) have been reported to have an increased risk of spontaneous abortion (SAB). Although previous studies have included only clinically recognized SABs, more than two-thirds of SABs MAy be clinically unrecognized. To determine whether fab work is associated with SAB, we recruited 152 fab and 251 nonfab workers, who collected urine samples for a 6-month period. Samples were analyzed by immunoradiometric assay for the presence of human chorionic gonadotropin to detect early fetal losses. Approximately 63% of fab and 46% of nonfab pregnancies ended in SAB [adjusted relative risk (RR) = 1.25; 95% confidence interval (CI) = 0.63-1.76]. Similar RR were seen for women who worked in dopant and thin-film processes (adjusted RR = 1.30; 95% CI = 0.51-1.96) or in MAsking (adjusted RR = 1.30; 95% CI = 0.59-1.84). The four pregnancies among women who worked with ethylene-based glycol ethers ended in SAB.     

Occupational paternal exposure to benzene and risk of spontaneous abortion.

OBJECTIVE--The purpose of this study was to evaluate the risk of spontaneous abortion among the wives of male workers occupationally exposed to benzene. METHODS--The wives of 823 men working in two chemical plants at the time of the study were asked to complete a questionnaire describing their pregnancies. The analysis of the 1739 pregnancies that ended in a spontaneous abortion or a birth is presented. The firms' payroll records provided all workers' employment history, including dates. Benzene exposure, graded at two levels (< 5, > or = 5 ppm), was determined for every job, so that benzene exposure for each worker's entire professional life (at these companies) could be assessed. This information was linked to the dates of the pregnancies reported in the questionnaires to enable the exposure status of each pregnancy to be defined (1270 non-exposed and 274 exposed). The frequency of spontaneous abortion, defined as the number of spontaneous abortions divided by the total of spontaneous abortions and births was evaluated. RESULTS--When adjusted for tobacco consumption, mother's age and pregnancy order, the odds ratio of the association between paternal exposure to approximately 5 ppm of benzene and the risk of spontaneous abortion was close to and statistically not different from unity (OR = 1.1; 95% CI (0.7-1.8). CONCLUSION--In this study paternal exposure to benzene did not increase the risk of spontaneous abortion.     

Risk of ectopic pregnancy and previous induced abortion.

OBJECTIVES: This study investigated the role of prior history of induced abortion in subsequent ectopic pregnancies. METHODS: Data from two French case-control studies were used to examine the effect of induced abortion on ectopic pregnancy risk. Case patients (n = 570) were women admitted for ectopic pregnancy during the study period; controls (n = 1385) were women who delivered in the same center. RESULTS: The analysis among women with no previous ectopic pregnancy showed that, after control for the main ectopic pregnancy risk factors, prior induced abortion was associated with an increased risk of ectopic pregnancy (odds ratio [OR] = 1.5, 95% confidence interval [CI] = 1.0, 2.0); there was a significant trend between number of previous induced abortions and ectopic pregnancy risk (ORs = 1.4 for 1 previous induced abortion and 1.9 for 2 or more). CONCLUSIONS: This study suggests that induced abortion may be a risk factor for ectopic pregnancy for women with no previous ectopic pregnancy, particularly in the case of women who have had several induced abortions.     

医护人员职业接触抗肿瘤药物不良妊娠结局及其影响因素调查

目的 调查职业接触抗肿瘤药物（antineoplastic drugs,ADs）医护人员不良妊娠结局现状,探讨其影响因素,改善医护人员职业防护。方法 对深圳市3家医院235名医护人员进行问卷调查,其中接触组119人（孕次153次）,对照组116人（孕次156次）。获取两组研究对象一般资料,比较两组不良妊娠结局（自然流产、胚胎停止发育、畸胎及死胎）发生率,并采用二元logistic回归分析接触组发生不良妊娠结局的影响因素。结果 接触组22名医护人员发生不良妊娠结局,其不良妊娠结局发生率为18.5%,接触组发生不良妊娠结局的风险是对照组的8.543倍（P <0.001）。二元logistic回归分析结果显示：ADs接触年限增加（OR=1.181,95%CI=1.004～1.389,P=0.044）是医护人员不良妊娠结局的危险因素,参与医院开设课程（OR=0.185,95%CI=0.036～0.954）、科室培训（OR=0.056,95%CI=0.005～0.633）及同事间交流学习ADs相关危害知识（OR=0.094,95%CI=0.015～0.605）、处理ADs时使用N95及以上...