Environews
NIEHS NEWS | NIEHS Lends a Hand
The havoc wrought by Hurricane Katrina brought the residents along the Gulf Coast the need for both immediate and long-term environmental health assistance. Among those providing expert help have been NIEHS staff and their academic, federal, and research partners. This article (p. A28) describes some of their initiatives to help the hurricane victims.
FOCUS | Portrait of an Environmental Disaster
Identifying and rectifying the environmental damage caused by the winds and waters of Hurricane Katrina will challenge scientists for months and even years to come. Combating the multitude of potential health threats is a major objective of federal, state, local, and private organizations. This article (p. A32) discusses the environmental health hazards created by Katrina and looks at some solutions offered by various public health and relief agencies.
SPHERES OF INFLUENCE | Resurrecting Wetlands
The flooding caused during the 2005 hurricane season has emphasized the critical need for wetland conservation and restoration along the Louisiana coast. Despite warnings from experts over the past several decades, the erosion of wetlands has continued unabated, and now requires urgent and thoughtful attention before another catastrophe strikes. This article (p. A40) looks at how the region's history has shaped its landscape and examines some strategies proposed to resurrect the wetlands.
INNOVATIONS | When It Absolutely, Positively Has to Be a Levee . . .
The Dutch are masters of the art of using natural resources to divert water and protect coastal cities from the dangers of flooding. At the same time, new risk analysis methods and the use of electronic sensors to gauge the structural integrity of bridges, dams, and levees are also proving to be valuable resources. This article (p. A44) describes how some of these low- and high-tech methods are being applied to new and existing levee systems.
Commentary
EXPOSURE ASSESSMENT | A Case Study of Tire Crumb Use on Playgrounds
Physicians and public health professionals working with the U.S. Environmental Protection Agency's Region 8 Pediatric Environmental Health Specialty Unit (PEHSU) received telephone calls requesting information regarding the safety of recycled tire crumb as a playground surface constituent. Callers were informed by the PEHSU that no evidence existed suggesting harm from intended use of the product, but gaps in knowledge about the product were identified and communicated. Anderson et al. (p. 1) use the case as a model to present an approach to similar environmental medicine questions.
Reviews
TOXICOGENOMICS | DNA Microarray for Toxicology and Ecotoxicology
The measurements of gene expression levels, upon exposure to a chemical, can be used both to provide information about the mechanism of action of the toxicant and to form a sort of "genetic signature" for the identification of toxic products. The development of high-quality, commercially available gene arrays has allowed this technology to become a standard tool in molecular toxicology. Lettieri (p. 4) reviews the practical use of gene expression profiling in toxicology and the progress toward the development of stressor-specific signatures in gene expression profiling for ecotoxicology.
RISK CHARACTERIZATION | Revisiting the Safety of Pesticides
The quality and quantity of the data about the risk posed to humans by individual pesticides vary considerably. Unlike obvious birth defects, most developmental effects cannot be seen at birth or even later in life. Instead, brain and nervous system disturbances are expressed in terms of how an individual behaves and functions. Colborn (p. 10) challenges the protective value of current pesticide risk assessment strategies in light of the vast numbers of pesticides on the market and the vast number of possible target tissues and end points that often differ depending upon timing of exposure.
Research
CANCER | Mortality in PCB-Capacitor Manufacturing
An Indiana capacitor-manufacturing cohort (n = 3,569) was exposed to polychlorinated biphenyls (PCBs) from 1957 to 1977. The original study of mortality through 1984 found excess melanoma and brain cancer. Other studies of PCB-exposed individuals have found excess non-Hodgkin lymphoma and rectal, liver, biliary tract, and gallbladder cancer. Ruder et al. (p. 18) have updated mortality through 1998 in this cohort. Findings of excess melanoma and brain cancer mortality confirm results of the original study. Melanoma mortality was not associated with estimated cumulative exposure. Brain cancer mortality did not demonstrate a clear dose-response relationship with estimated cumulative exposure.
GASTROINTESTINAL DISEASE | Rapidly Measured Indicators of Water Quality and Illness
Standard methods to measure recreational water quality require at least 24 hr to obtain results. Recent methods have been developed to measure recreational water quality in ≤ 2 hr. Wade et al. (p. 24) conducted a prospective study of beachgoers at two Great Lakes beaches to examine the association between recreational water quality obtained using rapid methods, and gastrointestinal (GI) illness after swimming. Enterococcus samples collected at 0800 hr were predictive of GI illness that day. The association between Enterococcus and illness strengthened as time spent swimming in the water increased. This is the first study to show that water quality measured by rapid methods can predict swimming-associated health effects.
Also see Science Selections, p. A48
POPULATION HEALTH | Fine Particulates and Mortality in California
Relatively few studies have investigated the relationship of mortality with fine particles [PM < 2.5 µm in diameter (PM2.5)] in a multicity setting. Ostro et al. (p. 29) examined associations between PM2.5 and daily mortality in nine heavily populated California counties using data from 1999 through 2002. The analysis revealed associations of PM2.5 levels with several mortality categories. A 10-µg/m3 change in 2-day average PM2.5 concentration corresponded to a 0.6% increase in all-cause mortality, with similar or greater effect estimates for subpopulations and mortality subcategories, including respiratory disease, cardiovascular disease, diabetes, age > 65 years, females, deaths out of the hospital, and non-high school graduates.
NEURODEVELOPMENT | Perinatal Exposure to ETS
Perinatal environmental tobacco smoke (ETS) exposure in humans causes neurobehavioral deficits. After exposing rhesus monkeys to ETS during gestation and through 13 months postnatally, or postnatally only (6-13 months), Slotkin et al. (p. 34) examined cerebrocortical regions and the midbrain for cell damage markers and lipid peroxidation. For perinatal ETS, two archetypal patterns were seen, one characterized by cell loss and corresponding increases in cell size, and a second pattern suggesting replacement of larger neuronal cells with smaller and more numerous glia. Results provide a mechanistic connection between perinatal ETS exposure and neurobehavioral anomalies, and emphasize the importance of restricting ETS exposure in young children.
ENVIRONMENTAL TOXICOLOGY | Reproductive Disruption in Wild Fish
Fish that live in rivers receiving municipal and industrial discharges may experience endocrine disruption as a result of exposure to anthropogenic pollutants. Fentress et al. (p. 40) evaluated the hormonal status of wild fish in a U.S. river receiving unbleached kraft and recycled pulp mill effluent. Sex steroid hormones were measured in male and female longear sunfish captured at sites near the effluent outfall. Kraft pulp mill effluent did not affect male reproductive physiology but did suppress female testosterone and vitellogenin levels when effluent constituted ≥ 1% of river flow. Masculinization was not observed. Longear sunfish experienced moderate reproductive suppression in response to unbleached kraft and recycled pulp mill effluent.
ENVIRONMENTAL TOXICOLOGY | Atrazine and Survival of Salamanders
Rohr et al. (p. 46) tested the contribution of exposure, density-mediated, and carryover effects on net survival by exposing embryos and larvae of the streamside salamander (Ambystoma barbouri) to atrazine (0, 4, 40, and 400 ppb; 3 ppb is the U.S. drinking water maximum) and quantifying survival during exposure and 14 months after exposure. Salamanders exposed to ≥ 4 ppb atrazine had significantly lower survival than control animals. The greatest change in survival occurred at low exposure concentrations. Together with evidence that low levels of atrazine impair amphibian gonadal development, the results here raise concerns about the role of atrazine in amphibian declines and highlight the importance of persistent, postexposure effects of xenobiotics on environmental health.
RESPIRATORY DISEASE | Ultrafine Particles and Blood Leukocytes
Ultrafine particles (UFPs) may contribute to respiratory and cardiovascular morbidity and mortality. Frampton et al. (p. 51) tested the hypothesis that inhalation of carbon UFPs has vascular effects in healthy and asthmatic subjects, detectable as alterations in blood leukocyte expression of adhesion molecules. In subjects with asthma, UFP exposure with exercise reduced expression of CD11b on monocytes and eosinophils and CD54 on granulocytes. Particle exposure also reduced the percentage of CD4+ T cells, basophils, and eosinophils. Inhalation of elemental carbon UFPs altered peripheral blood leukocyte distribution and expression of adhesion molecules in a pattern consistent with increased retention of leukocytes in the pulmonary vascular bed.
EXPOSURE ASSESSMENT | Indoor Mercury Vapor in Residential Buildings
Garetano et al. (p. 59) compared mercury vapor concentration in common areas of residential buildings with that in outdoor air in two New Jersey cities where mercury is used in cultural practices. Outdoor mercury vapor averaged 5 ng/m3, whereas the mean indoor mercury was 25 ng/m3. Twenty-one percent of buildings had mean mercury vapor concentrations in hallways that exceeded the 95th percentile of outdoor mercury vapor concentration (17 ng/m3), whereas 35% of buildings had maximum mercury vapor concentrations that exceeded the 95th percentile of outdoor mercury concentration. The highest indoor average mercury vapor concentration was 299 ng/m3, and the maximum point concentration was 2,022 ng/m3. These findings provide sufficient evidence of indoor mercury sources to warrant further investigation.
ENVIRONMENTAL TOXICOLOGY | Land Snails as Bioindicators of Vehicular Pollution
Regoli et al. (p. 63) evaluated an ecotoxicologic approach to bioaccumulation and toxicologic effects caused by airborne pollutants using the land snail Helix aspersa caged in five urban locations in Ancona, Italy. After 4 weeks, trace metals (cadmium, chromium, copper, iron, manganese, nickel, lead, zinc) and polycyclic aromatic hydrocarbons (PAHs) were measured and these data integrated with the analyses of molecular and biochemical responses. Results revealed accumulation of metals and PAHs in digestive tissues of snails maintained in more traffic-congested sites. The overall results of this exploratory study suggest the utility of H. aspersa as sentinel organism for biomonitoring the biologic impact of atmospheric pollution in urban areas.
ENVIRONMENTAL TOXICOLOGY | Organochlorines and Loggerhead Turtle Immunity
Organochlorine contaminants (OCs) such as polychlorinated biphenyls (PCBs) and pesticides modulate immune responses in rodents, wildlife, and humans. Keller et al. (p. 70) examined the effects of OCs on immunity in free-ranging loggerhead sea turtles. Mitogen-induced lymphocyte proliferation responses, lysozyme activity, and OC concentrations were measured in blood samples. The correlative observations suggest that chronic exposure to OCs may suppress innate immunity and enhance certain lymphocyte functions. The contaminants increased phytohemagglutinin and phorbol 12,13-dibutyrate (PDB)-induced proliferation at concentrations below those that affected cell viability. Concentrations that enhanced PDB-induced proliferation in vitro were similar to concentrations measured in turtles with the highest proliferative responses.
ENVIRONMENTAL TOXICOLOGY | Resistance to PCBs in Tomcod from the Hudson River
Atlantic tomcod (Microgadus tomcod) from the Hudson River, New York, have developed resistance to polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (PCDDs) but not to polycyclic aromatic hydrocarbons (PAHs). Resistance is heritable and manifests at early-life-stage toxic end points and in inducibility of cytochrome P4501A (CYP1A) mRNA expression. Yuan et al. (p. 77) determined the geographic extent of resistance to CYP1A mRNA induction by PCBs in the Hudson River tomcod population. Results indicate that tomcod from the Hudson River may represent the most geographically expansive population of vertebrates with resistance to chemical pollutants that has been characterized.
TOXICOGENOMICS | Effects of Depleted Uranium on Cells and Gene Expression
Depleted uranium (DU) is a by-product of uranium enrichment and shares chemical properties with natural and enriched uranium. To investigate the toxic effects of environmental DU exposure on the immune system, Wan et al. (p. 85) examined the influences of DU on viability and immune function as well as on cytokine gene expression. Microarray and real-time reverse-transcriptase polymerase chain reaction analyses revealed that DU alters gene expression patterns, indicating a possible involvement of DU in cancer development, autoimmune diseases, and T helper 2 polarization of T cells. The results are a first step in identifying molecular targets for DU toxicity and the elucidation of molecular mechanisms for immune modulation.
TOXICOGENOMICS | In Vitro Toxicogenomics: An Interlaboratory Study
Genomics technologies are relatively new and their applications require further investigation. When these technologies are applied to in vitro experiments, two major issues should be clarified: a) can in vitro toxicity studies, in combination with genomics analyses, be used to predict the toxicity of a compound, and b) are the toxicogenomics data reproducible between laboratories? Beekman et al. (p. 92) evaluated gene expression patterns from cultured rat primary hepatocytes incubated with methapyrilene (MP) in an interlaboratory study at four pharmaceutical companies. The results correctly identified MP in an independently generated in vitro database, underlining that in vitro toxicogenomics could be a predictive tool for toxicity.
TOXICOLOGY | Estrogen-Like Properties of Fluorotelomer Alcohols
Maras et al. (p. 100) investigated estrogen-like properties of five perfluorinated compounds using a combination of three in vitro assays. The E-screen assay detected proliferation-promoting capacity of the fluorotelomer alcohols 1H,1H,2H,2H-perfluorooctan-1-ol (6:2 FTOH) and 1H,1H,2H,2H-perfluoro-decan-1-ol (8:2 FTOH). The more widely environmentally distributed compounds perfluoro-1-octane sulfonate, perfluorooctanoic acid, and perfluorononanoic acid did not seem to possess this hormone-dependent proliferation capacity. There was also a small but relevant up-regulation of the estrogen receptor as a consequence of exposures to 6:2 FTOH or 8:2 FTOH. The latter finding suggests an alternative mode of action of the fluorotelomer alcohols compared with that of reference 17β-estradiol.
ENDOCRINE SYSTEM | Bisphenol A Induces Insulin Resistance
Pancreatic β-cells store and release insulin, the main hormone involved in blood glucose homeostasis. Alonso-Magdalena et al. (p. 106) show that bisphenol A (BPA) imitates 17β-estradiol (E2) effects in vivo on blood glucose homeostasis through genomic and nongenomic pathways. The exposure of adult mice to a single low dose of either E2 or BPA induces a rapid decrease in glycemia that correlates with a rise of plasma insulin. These results unveil the link between environmental estrogens and insulin resistance and suggest that either abnormal levels of endogenous estrogens or environmental estrogen exposure enhance the risk of developing type 2 diabetes mellitus.
Also see Science Selections, p. A48
ENVIRONMENTAL MEDICINe
CANCER | Serum Cadmium and Pancreatic Cancer
The Northeast Nile Delta region has a high incidence of early-onset pancreatic cancer. Epidemiologic studies suggest that cadmium plays a role in the development of pancreatic cancer. Kriegel et al. (p. 113) measured serum cadmium levels in pancreatic cancer patients and noncancer subjects from the same region in Egypt. There was a significant difference between the mean serum cadmium levels in patients versus comparison subjects but not in age, sex, residence, occupation, or smoking status. The results suggest that pancreatic cancer in the East Nile Delta region is significantly associated with high levels of serum cadmium and farming.
CARDIOVASCULAR DISEASE | Paroxysmal Atrial Fibrillation and Ambient Air Pollution
Rich et al. (p. 120) assessed the association between ambient air pollution and episodes of paroxysmal atrial fibrillation (PAF) episodes among patients with implantable cardioverter defibrillators (ICD) using a case-crossover study design. Results indicate a significant positive association between episodes of PAF and increased ozone concentration (22 ppb) in the hour before the arrhythmia. The risk estimate for a longer (24-hr) moving average was smaller, suggesting an immediate effect. Positive, but not significant, risks were associated with fine particles, nitrogen dioxide, and black carbon. Increased ambient ozone pollution was associated with increased risk of episodes of rapid ventricular response caused by PAF.
CHILDREN'S HEALTH
NEUROBEHAVIORAL DISEASE | Water Manganese and Children's Intellectual Function
Exposure to manganese via inhalation produces neurotoxicity in adults, but little is known about the consequences of exposure via drinking water in children. Wasserman et al. (p. 124) report results of a cross-sectional investigation of intellectual function in 10-year-old children in Bangladesh, who had been consuming well water with an average concentration of 793 µg Mn/L and 3 µg arsenic/L. After adjustment for sociodemographic covariates, water Mn was associated with reduced Full-Scale, Performance, and Verbal raw scores in a dose-response fashion; a low level of As in water had no effect.
Also see Science Selections, p. A50
CHILDREN'S HEALTH | Blood Lead and Method of Water Fluoridation
Some have hypothesized that community water containing sodium silicofluoride and hydrofluosilicic acid may increase blood lead concentrations (BLCs) in children by leaching of lead from water conduits and by increasing absorption of lead from water. Macek et al. (p. 130) evaluated the relation between water fluoridation method and BLCs in children. Geometric mean BLCs for water fluoridation methods were 2.40 µg/dL (sodium silicofluoride), 2.34 µg/dL (hydrofluosilicic acid), 1.78 µg/dL (sodium fluoride), 2.24 µg/dL (natural fluoride and no fluoride), and 2.14 µg/dL (unknown/mixed status). These findings do not support concerns that silicofluorides in community water systems cause higher BLCs in children.
Also see Science Selections, p. A49
EXPOSURE ASSESSMENT | Endotoxin Exposure Corrected for Measurement Error
Exposure to elevated levels of endotoxin in family-room dust was previously observed to be significantly associated with increased wheeze in the first year of life. It is likely that family-room dust endotoxin was a surrogate for airborne endotoxin exposure. A related substudy characterized the relationship between levels of airborne household endotoxin and the level of endotoxin present in house dust. Horick et al. (p. 135) reexamine the relationship between endotoxin exposure and wheeze under the assumption that the level of airborne endotoxin in the home is the exposure of interest and that the amount of endotoxin in household dust is a surrogate for this exposure.
BUILT ENVIRONMENT | IAQ Programs in U.S. Schools
Moglia et al. (p. 141) determined the extent to which U.S. schools implement indoor air quality (IAQ) programs. Forty-two percent of schools have an IAQ management program, and there has been sustained growth from 1998 through 2002 in the number of schools with programs. The IAQ Practice Index scores varied widely, suggesting that having a program is not equivalent to implementation. Respondents indicated that their IAQ programs improved workplace satisfaction, fewer asthma attacks and visits to the school nurse, and lower absenteeism. When actively supported by the school administration, the program appears to be a valuable factor in improving the learning environment.