Congenital anomalies associated with maternal exposure to oxydemeton-methyl

Thirty-five workers became ill after they entered a cauliflower field contaminated with residues of three different insecticides, the organophosphates oxydemeton-methyl (Metasystox-R) and mevinphos (Phosdrin), and a carbamate, methomyl (Lannate). One crew member was pregnant with a 4-week-old fetus. At birth, the 3200-g female infant had multiple cardiac defects, bilateral optic nerve colobomas, microphthalmia of the left eye, cerebral and cerebellar atrophy, and facial anomalies. The cardiac defects included ventricular and atrial septal defects, stenosis of the pulmonary artery, and a patent ductus arteriosus. The child died at 14 days of age. There was no family history of birth defects, nor any maternal risk factor present, except that doxylamine (Bendectin) had been prescribed at 9 weeks fetal age. It is unlikely that doxylamine was responsible for the observed anomalies. Of the three chemicals involved, reproductive effects in test organisms have been observed only with oxydemeton-methyl. This case represents the first report of human malformations associated with prenatal exposure to this chemical. Further studies may be warranted to determine if a causal relationship exists.     

Assessment of exposure to laser radiation in research laboratories

The problem of laser safety is now topical due to the wide use of laser systems in different working environments. The program of prevention and protection prescribed by law 626/94 gives general rules for the elimination (where possible) and/or reduction of risk factors. For this purpose, it is important to determine the parameters that characterize such risks. The Maximum Permissible Exposure (MPE) and the Nominal Ocular Hazard Distance (NOHD) are the most important parameters of laser safety. The evaluation of these parameters requires a detailed knowledge of the standards and of the various techniques which are necessary to measure them. In particular, the MPE parameters are obtained by CEI EN 60825-1 standard in relation to wavelength and emission duration of the investigated laser. Exposure to laser radiation is usually measured in terms of irradiance (W/m2) or radiant exposure (J/m2). The experimental values of irradiance must be compared with the MPE parameters obtained by safety standards. When the values of irradiance exceed the MPE parameters then the NOHD values must to be calculated. The aim of this paper is to offer a general view of the methods for measuring the above-mentioned parameters for the laser sources that are most widely used in research environments and to compare such parameters with those recommended by safety standards. Our results indicate that for almost all the laser sources analysed, the measured exposure values were greater than the MPE recommended by standards, both for eyes and skin. High values of NOHD indicate that it is necessary to use eye protection, beam stops or attenuators at the end of the useful beam path in normal working conditions and especially in research laboratories in which these conditions can often change.     

Pregnancy outcome of personnel in Swedish biomedical research laboratories

Possible hazardous effects of laboratory work on the reproduction outcomes of female laboratory personnel in Sweden from 1990 to 1994 were investigated in a questionnaire-based study (n = 1052) by comparison with personnel in non-laboratory departments. The individual woman constituted the primary sampling unit, with her pregnancies defined as the unit of analysis. Allowance for dependence between different pregnancies of the same woman was considered by applying random effect models. With regard to spontaneous abortions, no elevated odds ratio was found for laboratory work in general, but an odds ratio of 2.3 and a 95% confidence interval of 0.9 to 5.9 (n = 856) was connected to working with chloroform. The odds ratio for large for gestational age infants in association with the mother's laboratory work was 1.9 (confidence interval, 0.7 to 5.2). The result with regard to spontaneous abortion partly supports previously reported increased risks of miscarriage related to laboratory work with solvents.     

High-purity water supplies for biomedical research laboratories.

A quantitative bacteriological survey of high-purity water systems used in biomedical research laboratories at the National Institutes of Health revealed great variations among the systems. In general, distilled water had significantly lower contamination levels than deionized water. Interviews with investigators revealed their conceptions about the importance of bacterial contamination in high-purity water and some expectations about bacterial quality. Guidelines are suggested for the use of water from systems of varying quality.     

Inhalation exposures to acrylamide in biomedical laboratories

This study evaluated airborne acrylamide exposures experienced by laboratory personnel using either crystalline or commercially available solutions of acrylamide to make polyacrylamide gels. Exposures were monitored for a short-term (15-min) sampling period, during the weighing of the crystalline acrylamide or the removal of the acrylamide solution from its original container, and a long-term period, during which a sample was collected for as long as the subject was potentially exposed to acrylamide. Mean air concentrations for the 15-min exposures were 7.20 +/- 5.64 micrograms/m3 and 5.81 +/- 4.53 micrograms/m3 for the users of crystalline and solution acrylamide, respectively, although this difference was not statistically significant (p > 0.05). Mean concentrations for the long-term exposures were 12.77 +/- 24.20 micrograms/m3 for workers employing crystalline acrylamide and 4.22 +/- 7.05 micrograms/m3 for personnel using acrylamide solutions. This difference was also not statistically significant. Although the results indicate that the research laboratory personnel were generally exposed to measurable concentrations of acrylamide, with several subjects exposed to elevated levels, the calculated 8-hour time-weighted average exposures were below current occupational exposure limits. However, because the neurotoxic effects of acrylamide are cumulative and it is a suspected carcinogen, all exposures should be kept as low as reasonably achievable.     

Adverse reproduction outcomes among employees working in biomedical research laboratories

OBJECTIVES: The aim of the study was to investigate reproductive outcomes such as birthweight, preterm births, and postterrm births among women working in research laboratories while pregnant. METHODS: Female university personnel were identified from a source cohort of Swedish laboratory employees, and the database was linked to the medical birth register. The first births of the women were included in the analysis, 249 pregnancies among the women with laboratory work and 613 pregnancies among the women without laboratory tasks. Information about exposure to various laboratory agents was obtained from a previous questionnaire investigation at the research group level according to a specific definition. The ponderal index and ratio between observed and expected birthweights were calculated. Logistic regression models were used for analyses of dichotomous outcomes (preterm, postterrm and birthweight). RESULTS: Exposure to laboratory work with solvents was associated with an increased risk of preterm births, the estimated odds ratio (OR) being 3.4 (1.0 < 95% confidence interval < 11.9). An association with work with bacteria was also observed for postterm births (OR 2.7, 1.0 < or = 95% confidence interval < 7.4). CONCLUSIONS: There was a slightly elevated risk for some reproductive outcomes among the women working with certain laboratory tasks, specifically for preterm and postterm births in relation to work with solvents and bacteria.     

Factors related to biomedical research productivity in Asian countries

By and large, biomedical research is not a priority sector in Asian countries due to many factors. Lack of resources and trained manpower are certainly among these factors. We investigated the factors related to biomedical research productivity in Asian countries based on Medline data. The number of biomedical articles published in the indexed journals from each country of Asia and Oceania during 1990-1998 was used as a surrogate of total biomedical research productivity. Multiple regression analysis revealed that low gross national product per capita (p<0.013), insufficient number of physicians (p<0.047), and inadequate public spending on the health sector (p<0.049) were responsible for the meager number of biomedical publications in Asian countries.     

Congenital malformations and exposure to high-frequency electromagnetic radiation among Danish physiotherapists

A cluster initiated the present case-referent study to assess the relation between exposure to high-frequency electromagnetic radiation and congenital malformations. Through the linkage of a cohort formed from a union file of Danish physiotherapists with complete national registers of pregnancy outcome, cases (pregnancies terminated by the birth of a malformed child) and referents were identified. From responses in a blinded telephone interview without knowledge of case status, exposure to high-frequency electromagnetic radiation in the first month of pregnancy was assessed. Indices reflecting duration of exposure ("time") and maximum level of exposure ("peak") were composed. After a 7% dropout 54 cases and 247 referents were interviewed. No statistically significant associations between pregnancy outcome and high-frequency electromagnetic radiation were found (odds ratio 1.7, 95% confidence interval 0.6-4.3).     

Congenital malformations and maternal occupation in Finland: multivariate analysis.

The Finnish Register of Congenital Malformations was used in a multivariate analysis to explore the associations between maternal occupation in industry and children born with central nervous system (CNS) or musculoskeletal or oral cleft malformations. Possible confounding factors were selected in preliminary screening of risk indicators for malformations. These factors included characteristics of the mother, the child, and the family; maternal illnesses; an maternal medication at the time of pregnancy. Tobacco smoking was a confounding factor for all type of malformations; number of children born to the mother, maternal age, malformations in the family, number of rooms occupied by the family, sex of the child, threatened abortion, and continuous medication of the mother during the first trimester confounded the association for certain type of malformations. After adjusting for confounding factors, maternal occupation in industrial trades significantly correlated with CNS, oral cleft, and musculoskeletal malformation in the offspring. Maternal occupation in industry and construction only was significantly associated with CNS malformations in the offspring but the associations with oral cleft and musculoskeletal malformations were not significant.     

Adverse pregnancy outcomes in offspring of fathers working in biomedical research laboratories

BACKGROUND: Laboratory work may constitute a possible health hazard for workers as well as for their offspring, and involves a wide range of exposures, such as organic solvents, carcinogenic agents, ionizing radiation, and/or microbiological agents. Adverse pregnancy outcomes in the offspring of male employees in biomedical research laboratories are examined. METHODS: Offspring to males employed 1970-1989 at four Swedish universities were identified via the Medical Birth Register (MBR), along with other pregnancy parameters. Offspring of fathers with laboratory work (n = 2,281) is considered exposed, and of non-laboratory employees unexposed (n = 1,909). Exposure data were obtained by questionnaires to research group leaders. Logistic regression analysis estimated odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Paternal laboratory work in general showed no statistically significant increased ORs concerning birth weight and/or gestational age, but work specifically with radioactive isotopes gave OR 1.8 (CI 1.0-3.2) for high birth weight and a relative risk of 1.2 (CI 1.0-1.4) for sex ratio (male/female). CONCLUSIONS: There was no clear association between periconceptional paternal laboratory work and adverse reproductive outcomes, but use of radioactive isotopes showed increased OR for high birth weight in offspring.     

Congenital malformations and maternal occupation: a registry based case-control study.

OBJECTIVES: To investigate the relations between congenital malformations and maternal occupation during pregnancy with a registry based case-control study. METHODS: Analysis was performed on data derived from the Florence Eurocat registry surveillance programme. The study included cases with isolated conditions, including chromosomal anomalies (n = 1351), cases with multiple anomalies registered during the 1980-91 period (n = 440), and babies with no congenital malformations recognised at birth who were born from 1982 to 1989 and selected as controls (n = 3223). 11 categories were defined, 10 including cases with isolated malformations and one for cases with multiple congenital anomalies. Four categories of maternal occupation were selected for the study. Odds ratio (OR) values were adjusted for maternal origin, maternal and paternal education, number of previous live births, illness during pregnancy, and maternal age when the group of chromosomal anomalies was analysed. RESULTS: A notable and significant association between oral clefts and mothers involved in leather and shoe manufacturing was found (adjusted OR 3.9; 99% confidence interval (99% CI) 1.5 to 9.8) and the risk consistently increased when considering cases with isolated cleft palate separately (OR 5.4; 95% CI 1.8 to 13.4). Moreover, a significant risk was identified for the association between multiple anomalies and textile dye workers (adjusted OR 1.9; 99% CI 1.0 to 3.8). CONCLUSIONS: This study indicates a notable, significant relation between maternal occupation as a pelt or leather worker and orofacial clefts in offspring. This finding is in agreement with the suggested inheritance models. The dilution effect due to studying large and heterogeneous groups of workers and occupations limits the value of the study; but it provides a good example of the use of a large database to search for teratogenic risk with the aid of malformation registries.     

Chemical hazards related to clandestine drug laboratories

The number of clandestine drug laboratories in the United States and Europe has increased as a result of the rising popularity of methamphetamine, Ecstasy, and gamma-hydroxybutyrate among young people and drug abusers, and a shift from complex production procedures for these drugs to simpler "cold cook" methods involving household chemicals. Fires, explosions, corrosive chemicals, and toxic substances at clandestine drug laboratories have caused injuries and deaths among police officers, firefighters, and the public. Impurities in clandestine synthetic drugs have also caused injuries among people consuming the drugs. Information about these hazards should be communicated to public safety professionals and young people to reduce the number of injuries and deaths.     

Congenital cardiovascular malformations. January to July 1987

This paper deals with the study of 23 patients with congenital cardiovascular malformations. Causes of such malformations, as well as symptoms for a positive diagnosis, are investigated. There was only four deaths within the cases under study, which makes evident attention given to these patients.