Maternal occupational noise exposure during pregnancy and children's early language acquisition.

INTRODUCTION: Noise exposure during pregnancy may affect a child's auditory system, which may disturb fetal learning and language development. We examined the impact of occupational noise exposure during pregnancy on children's language acquisition at the age of one. METHODS: A cohort study was conducted among women working in the food industry, as kindergarten teachers, musicians, dental nurses, or pharmacists who had a child aged <1 year. The analyses covered 408 mother-child pairs. Language acquisition was measured using the Infant-Toddler Checklist. An occupational hygienist assessed noise exposure individually as no (N = 180), low (70-78 dB; N = 108) or moderate/high exposure (>79 dB; N = 120). RESULTS: Among the boys, the adjusted mean differences in language acquisition scores were -0.4 (95% CI -2.5, 1.8) for low, and -0.7 (95% CI -2.9, 1.4) for moderate/high exposure compared to no exposure. Among the girls the respective scores were +0.1 (95% CI -2.2, 2.5) and -0.1 (95% CI -2.3, 2.2). Among the children of kindergarten teachers, who were mainly exposed to human noise, low or moderate exposure was associated with lower language acquisition scores. The adjusted mean differences were -3.8 (95% CI -7.2, -0.4) for low and -4.9 (95% CI -8.6, -1.2) for moderate exposure. CONCLUSIONS: In general, we did not detect an association between maternal noise exposure and children's language acquisition among one-year-old children. However, the children of kindergarten teachers exposed to human noise had lower language acquisition scores than the children of the non-exposed participants. These suggestive findings merit further investigation by level and type of exposure.

Newly discovered KI, WU, and Merkel cell polyomaviruses: no evidence of mother-to-fetus transmission.

BACKGROUND: Three* human polyomaviruses have been discovered recently, KIPyV, WUPyV and MCPyV. These viruses appear to circulate ubiquitously; however, their clinical significance beyond Merkel cell carcinoma is almost completely unknown. In particular, nothing is known about their preponderance in vertical transmission. The aim of this study was to investigate the frequency of fetal infections by these viruses. We sought the three by PCR, and MCPyV also by real-time quantitative PCR (qPCR), from 535 fetal autopsy samples (heart, liver, placenta) from intrauterine fetal deaths (IUFDs) (N = 169), miscarriages (120) or induced abortions (246). We also measured the MCPyV IgG antibodies in the corresponding maternal sera (N = 462) mostly from the first trimester. RESULTS: No sample showed KIPyV or WUPyV DNA. Interestingly, one placenta was reproducibly PCR positive for MCPyV. Among the 462 corresponding pregnant women, 212 (45.9%) were MCPyV IgG seropositive. CONCLUSIONS: Our data suggest that none of the three emerging polyomaviruses often cause miscarriages or IUFDs, nor are they transmitted to fetuses. Yet, more than half the expectant mothers were susceptible to infection by the MCPyV.

Occupational exposure in dentistry and miscarriage.

BACKGROUND: Information on the reproductive effects of chemical exposures in dental work is sparse or inconsistent. AIM: To investigate whether dental workers exposed to acrylate compounds, mercury amalgam, solvents or disinfectants are at an increased risk of miscarriage. METHODS: The study was conducted among women dental workers and a comparison group of workers occupationally unexposed to dental restorative materials. Information on pregnancies was obtained from national registers and outpatient units of hospitals. Data on occupational exposure were obtained using postal questionnaires. The final study population included 222 cases of miscarriage and 498 controls (births). An occupational hygienist assessed exposure to acrylate compounds, disinfectants and solvents. Exposure to other agents was assessed on the basis of the questionnaire data. Odds ratios (ORs) and confidence intervals (CIs) were estimated using conditional logistic regression. RESULTS: The ORs adjusted for confounding factors were increased for moderate-exposure and high-exposure categories of mercury amalgam (OR 2.0, 95% CI 1.0 to 4.1 and OR 1.3, 95% CI 0.6 to 2.5, respectively). The risk was slightly increased for the highest-exposure category of 2-hydroxyethylmethacrylate (OR 1.4, 95% CI 0.7 to 2.6) and polymethylmethacrylate dust (OR 1.4, 95% CI 0.8 to 2.4). A slightly increased risk was also detected for likely exposure to organic solvents (OR 1.4, 95% CI 0.8 to 2.3) and disinfectants (OR 1.5, 95% CI 0.9 to 2.7). CONCLUSIONS: No strong association or consistent dose-response relationship was observed between exposure to chemical agents in dental work and the risk of miscarriage. A slightly increased risk was found for exposure to mercury amalgam, some acrylate compounds, solvents and disinfectants. These findings indicate that the possibility of a weak association between exposure to these agents and an increased risk of miscarriage cannot be excluded.

Results of common laboratory tests in solvent-exposed workers.

OBJECTIVES: The screening and identification of occupational liver or other organ-system injury related to long-term, low-level solvent exposure are difficult in clinical practice. We studied the feasibility of the use of common laboratory tests combined with a detailed exposure history. METHODS: The relationships between laboratory tests and exposure to organic solvents were studied in regression modelling adjusted to age, alcohol consumption, gender and body mass index (BMI). The subjects were 29 solvent-exposed workers and 19 referents. Laboratory tests included serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), carbohydrate-deficient transferrin (CDT), alkaline phosphatase (ALP), creatinine, cholesterol, HDL-cholesterol, triglycerides, blood glucose and total and conjugated bilirubin. Positive hepatitis serology, systemic diseases or medications with known hepatic effects and current pregnancy were exclusion criteria. The main exposures of each subject were identified. Current solvent exposure status, exposure during the past 3 months, exposure during the past 5 and 10 years, and total life-time exposure were recorded. RESULTS: AST (P=0.0031), ALT (P=0.0015) and cholesterol (P=0.0110) correlated positively with cumulative solvent exposure in the past 5 years, total bilirubin with current exposure (P=0.0380), and glucose with exposure in the past 5 (P<0.0001) and 10 (P=0.0003) years. Triglycerides correlated positively with exposure in the past 5 (P=0.0025) and 10 (P=0.0059) years and with life-time exposure (P=0.0005). Creatinine correlated negatively with exposure in the past 10 years (P=0.0300) and life-time exposure (P=0.0005). Most laboratory values were within the normal range. CONCLUSIONS: These results suggest a multi-system health effect of solvents. The laboratory data had some similarities with those in the metabolic syndrome. The screening and diagnostics of solvent-related conditions should be based on a thorough work history and a set of carefully selected laboratory tests. No single test seems sufficient for this purpose.

Effects of exposure to environmental tobacco smoke on reproductive health.

The scientific evidence on the effects of preconceptional and prenatal exposure to environmental tobacco smoke on reproductive health is reviewed in this article. The evidence is the most convincing for the adverse effects of environmental tobacco smoke on birthweight. In meta-analyses, exposure to environmental tobacco smoke has been estimated to reduce mean birthweight by about 25-40 grams. The majority of the studies on low birthweight also show a moderately or slightly increased risk among infants of exposed women. There is also some support for an association between high exposure to environmental tobacco smoke and preterm birth. The evidence on the effects of environmental tobacco smoke on spontaneous abortion and birth defects is weak and inconsistent. Very little is known about the impact of exposure on fertility, menstrual function, reproductive health of men, and childhood cancer. Further studies, paying attention to study design and careful exposure assessment, are therefore needed on these associations.