Archives of environmental health最新文献

The authors sought to determine levels of urinary cotinine and its association with collateral exposure to second-hand smoke in public health workers. Urinary cotinine was measured twice at 1-wk intervals in 28 public health workers or their spouses. Information on sources of second-hand smoke exposure and a dietary history were obtained from each participant. Geometric mean and median cotinine levels were 2.74 and 2.33 ng/mL, respectively. Only 6 instances of second-hand smoke exposure were reported from a combined 204 days of potential exposure, and these did not correspond to higher cotinine values. There was no association between consumption of foods containing nicotine and log-transformed urine cotinine levels (p = .80). The authors' analysis indicates dietary sources of nicotine are not important, even for persons with very low urinary cotinine levels. Further study is needed to determine sources of variation in urinary cotinine among largely unexposed populations.

Methylmercury is eliminated from the human body as glutathione (GSH) conjugates. GSH production is mediated by glutamyl-cysteine ligase (GCL) and conjugation by glutathione S-transferases (GST). In this study, the authors tested whether polymorphisms in GCL and GST genes modify methylmercury retention. Erythrocyte mercury concentration (EryHg), plasma polyunsaturated fatty acids (PPUFA), and genotype for GCLC, GCLM, GSTA1, GSTM1, GSTP1, and GSTT1 were determined in 365 individuals. A general linear model was developed for analyzing whether genotype modified the regression of EryHg on PPUFA. The presence of one variant allele for either GCLC-129 or GSTP1-114 was associated with higher EryHg and steeper regression slope. No similar trends were shown for GCLM, GSTA1, GSTM1, or GSTT1. These findings indicate that GCLC polymorphisms that affect GSH production also affect methylmercury retention, and that GSTP1 may play a role in conjugating methylmercury with GSH.

Using trend analysis, the author sought a possible association between perinatal mortality rates in West Germany, 1955-1993, and the fallout from atmospheric nuclear weapons testing in the years 1952-1993. The regression model used a continuously falling trend and a superimposed extra term that reflects the average strontium content in pregnant women. Mortality rates show an upward deviation that peaked in 1970. The model attributes more than 100,000 excess perinatal deaths to strontium in the fallout. The dose-response curve is curvilinear with a power of dose of 1.81 +/- 0.23. In addition, using a combined regression model, the author analyzed the two data subsets of perinatal mortality (i.e., stillbirth rate and early neonatal mortality). The strontium effect is 3.4 times greater on early infant deaths than on stillbirths. According to the prevailing wisdom, the fetus is protected against damage from ionizing radiation by a threshold dose of 50-200 mSv, but the doses from strontium in the fallout were well below 1 mSv/yr in Germany. The results reported here seem to contradict the existence of a threshold dose for perinatal mortality at low doses.

Although organophosphate (OP) insecticides have been recognized as having neuropathic potential, a relationship with Guillain-Barre syndrome (GBS) has not been previously confirmed. A cluster of 7 cases of GBS was noted over an 11-yr period in an isolated farming region in the Northern Cape Province of South Africa, an area subject to intensive aerial application of OP insecticides. Observed cases were more than 4 times higher than expected based on a Poisson probability distribution. Four cases were clustered in an area where the topography showed a marked hollow, and where spray drift of aerial OP insecticides was anticipated. The rate of GBS in this subcluster was more than 14 times higher than expected. The authors explored the hypothesis that aerial OP insecticide application was related to the raised incidence of GBS in this area and made suggestions for future research.

The health effects from prolonged low-level organophosphate exposure are unknown. We hypothesized that exposed individuals would show neuropsychological decrements when compared with unexposed individuals, and that cumulative organophosphate exposure would be correlated with neuropsychological performance. We used a quasiexperimental cross-sectional design to compare neuropsychological test scores among three groups: orchard sprayers exposed to organophosphates, and construction worker and pig farm workers who were not exposed. Relative to construction workers, orchard sprayers were significantly slower on negative statements of the syntactic reasoning test. However, we found no relationship between cumulative exposure and test response. The slower response of the orchard sprayers was apparently exposure-related, but we could not identify an underlying neurotoxic mechanism. Therefore, we are unable to conclude whether this is a specific cognitive effect, or a decrement arising on the most sensitive test employed.

The source of infection for travelers who develop Legionnaires' disease (LD) shortly after a journey abroad is difficult to ascertain. Infection is likely to have occurred abroad, but could also have occurred at the patient's own residence. The authors conducted a case-control study to determine risk for acquiring LD at home in the Netherlands after traveling abroad. They compared homes of 44 traveling LD patients with 44 homes of nontraveling LD patients, using logistic regression models. Geographic distribution was confounding the association between traveling and presence of Legionella spp. in residences; adjustment was necessary. In traveler's homes, legionellae were present more often, with crude and adjusted OR (95% CI) being 1.6 (0.5-5.0) and 1.4 (0.4-4.4), respectively. The authors' findings indicate that the patient's residence can be a potential source of infection after traveling.

One hundred fourteen male employees of a cotton spinning mill in western Germany participated in a cross-sectional study, the purpose of which was to clarify the dose effect of endotoxin exposure on respiratory symptoms. Airborne endotoxin exposures were classified as low (< or = 100 endotoxin units [EU]/m3), medium (> 100-450 EU/m3), or high (> 450 EU/m3), on the basis of endotoxin activity in the Limulus amoebocyte lysate assay. Age- and smoking-adjusted odds ratios (ORs) and confidence intervals (CIs) were estimated. The dose-response relationship between current endotoxin exposure and prevalence of wheezing (medium: OR = 2.15, 95% CI = 0.48-9.62; high: OR = 5.49, 95% CI = 1.17- 25.81) and cough (medium: OR = 2.11; 95% CI = 0.59-7.56; high: OR = 3.93; 95% CI = 1.02-15.12) was significant (test for linear trend: p values = 0.020 and 0.040, respectively). The association between exposure and wheezing was stronger among atopic workers. The higher prevalence of chest tightness and shortness of breath among workers with medium and high current endotoxin exposure did not reach statistical significance. The results suggested that there was a dose-dependent increase in bronchial symptoms, with significant effects occurring at exposures that exceeded 450 EU/m3.

The authors describe two patients with systemic vasculitis and prior occupational exposure to organic solvents. Systemic vasculitis should be considered a sentinel event for such exposures.

The Tranguch Gasoline Spill leaked 50,000-900,000 gallons of gasoline from underground storage tanks, potentially exposing an area of Hazle Township and Hazleton, Pennsylvania, to chronic low levels of benzene since at least 1990. A retrospective cohort study of 663 individuals representing 275 households assessed whether affected residents were at increased risk for cancer from 1990-2000 compared with the Pennsylvania populace. Age-adjusted standard incidence ratios (SIRs) were calculated using Pennsylvania rates to determine expected numbers. The age-adjusted SIR for the gasoline-affected area was 4.40 (95% confidence interval: 1.09-10.24) for leukemia. These results suggest an association between living within the area affected by the Tranguch Gasoline Spill and increased risk for leukemia.