Archives of environmental health最新文献

To investigate the effects of 12 monthly average air pollution levels on monthly prevalence of respiratory morbidity, the authors examined retrospective questionnaire data on 2034 4th-grade children from 12 Southern California communities that were enrolled in The Children's Health Study. Wheezing during the spring and summer months was associated with community levels of airborne particulate matter with a diameter < or = 10 microm (PM10) (odds ratio (OR) = 2.91; 95% confidence interval (CI) = 1.46-5.80), but was not associated with community levels of ozone, nitrogen dioxide, PM2.5 (diameter < or = 2.5), nitric acid, or formic acid. Logistic regression was performed on data stratified into two seasonal groups, spring/summer and fall/winter. Among asthmatics, the monthly prevalence of asthma medication use was associated with monthly levels of ozone, nitric acid, and acetic acid (OR = 1.80 [95%CI = 1.19-2.70]; OR = 1.80 [95%CI = 1.23-2.65]; OR = 1.57 [95% CI = 1.11-2.21]; respectively). Asthma medication use was more prevalent among children who spent more time outdoors--with consequential exposure to ozone--than among children who spent more time indoors (OR = 3.07 [95%CI = 1.61-5.86]; OR = 1.31 [95%CI = 0.47-2.71]; respectively). The authors concluded that monthly variations in some ambient air pollutants were associated with monthly respiratory morbidity among school children.

The authors estimated the number of premature deaths from particulate matter less than 2.5 microm (PM2.5) that would result from making 29 proposed fossil fuel power plants in Virginia operational. We used a U.S. Environmental Protection Agency air quality model (Climatological Regional Dispersion model) to calculate changes in ambient concentrations of PM2.5 and Cox proportional hazard modeling to calculate the resulting premature mortality. The model predicted that if all 29 plants were operational, PM2.5 concentrations would rise in 271 counties across 19 states 5 and increased average annual PM2.5 concentrations would result in a rate of 17 deaths per 37,900,026 people aged 30 yr and older (0.45 deaths per million, 95% confidence interval = 0.31, 0.59) per year by the end of 2004, increasing thereafter. Over a 6 yr period, 104 cumulative excess deaths would occur due to operations of these proposed plants. The authors recommend that precautionary principles be considered when policy decisions related to energy production from fossil fuels are made.

In this article, the researchers studied the prevalence of preterm births for women living near thermal power plants. The prevalence of delivery of preterm birth infants was significantly higher among women living within 3 km of a thermal power plant than among women living within 3-4 km of a plant. After controlling for several possible confounders (including maternal age, season, marital status, maternal education, infant gender, and birth site), the adjusted odds ratio was 1.14 (95% confidence interval, 1.01-1.30) for delivery of preterm infants for women living close to the thermal power plants. These data provide further support for the hypothesis that air pollution can affect the outcome of pregnancy, although a semiecological study cannot confirm a direct causal relationship.

Arsenic is the major risk factor for blackfoot disease, a peripheral vascular disease that has been endemic to the southwest coast of Taiwan for more than 50 yr because of the consumption of local artesian well water containing high levels of arsenic. Long-term arsenic exposure has been associated with kidney cancer mortality in a dose-response relationship. In the early 1960s, a tap water supply system was implemented in the blackfoot-endemic areas. After the mid-1970s, artesian well water was no longer used for drinking or cooking in the region. The authors examined whether kidney cancer mortality decreased after the elimination of arsenic exposure from artesian well water. Standardized mortality ratios for kidney cancer were calculated for the blackfoot-endemic area for the years 1971-2000. Study results showed that mortality from kidney cancer declined gradually during this time; therefore, the association of arsenic exposure with kidney cancer mortality was likely causal.

Field methods are needed to detect and monitor the organophosphate pesticide exposure of young children. Twenty children, aged 11 to 18 mo, living in an agricultural community along the United States/Mexico border were enrolled in a pilot study investigating methods to detect pesticide exposure. Healthy children were recruited at pediatric clinics with the informed consent of their parents. Venous blood samples were collected from children twice, 4 wk apart. Cholinesterase activity was compared in whole heparinized venous blood with venous blood samples dried on filter paper. Although the amount of activity in the dried blood was consistently less than in the heparinized blood, the activity was significantly correlated: Spearman r = .6 (p = 0.01). This dried blood method may be used during field studies to evaluate changes in cholinesterase values in children over time.

The authors conducted a cross-sectional study to determine blood lead levels in children who attended kindergarten schools and nurseries in Nicosia, Cyprus, and to correlate their findings with (a) home and school environments, (b) behavior of the children, and (c) socioeconomic characteristics. Capillary blood for lead assay was collected from March 2001 to September 2001 from children who lived and attended school in Nicosia. Children who lived and attended school in a rural setting served as controls. Parental questionnaires and interviews yielded information about socioeconomic background, environment, and children's habits and health. Overall findings indicated that children in Nicosia had mean blood lead levels similar to controls (i.e., <10 microg/dl)--the level of concern defined by the U.S. Centers for Disease Control and Prevention. The findings of our study likely represent high standards of hygiene adopted by parents and teachers, rather than knowledge embraced by parents and teachers about risks associated with lead exposure and sources of lead exposure.

A cross-sectional study was performed in one industrial (study) and one non-industrial (reference) town in Punjab State, northern India. Ambient air quality samples were collected and analyzed each week for 2 yr. Subjects were 3,603 individuals >15 yr old who were interviewed and whose lung functions were measured spirometrically. Their biomarkers were categorized in terms of obstructive or restrictive defects. Levels of total suspended particulates, nitrogen oxides, sulfur oxides, carbon monoxide, and ozone were significantly higher in the study town than in the reference town. The prevalence of chronic respiratory symptoms (cough, phlegm, breathlessness, or wheezing) was 27.9 and 20.3% in the study and reference towns, respectively (p < 0.05). That of obstructive ventilatory defect was 24.9 and 11.8% (p < 0.05), respectively. Logistic regression analysis showed that residence in the study town was independently associated with chronic respiratory symptoms (odds ratio [OR] = 1.5; 95% confidence interval [CI] = 1.2, 1.8; p < 0.001) and spirometric ventilatory defect (OR = 2.4; 95% CI = 2.0, 2.9; p < 0.001) after controlling for other demographic effects.

The authors compared the viability and infectivity of Cryptosporidium parvum oocysts in chlorinated tap water at various storage durations (i.e., 2 wk, 4 wk, 6 wk, or 8 wk) and at 2 cool temperatures (i.e., 10 degrees C and 4 degrees C), using in vitro (excystation) and in vivo (suckling mouse) methods. After 8 wk, mean oocyst excystation decreased to 33.4% and 26.7% at 10 degrees C and 4 degrees C, respectively. Suckling mice infectivity was higher after storage at 10 degrees C than after storage at 4 degrees C. These data suggest that Cryptosporidium parvum oocysts can survive and remain infectious for 8 wk in cool chlorinated tap water.