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PubMed2006

Pilot survey of subway and bus stop noise levels.

Excessive noise exposure is a serious global urban health problem, adversely affecting millions of people. One often cited source of urban noise is mass transit, particularly subway systems. As a first step in determining risk within this context, we recently conducted an environmental survey of noise levels of the New York City transit system. Over 90 noise measurements were made using a sound level meter. Average and maximum noise levels were measured on subway platforms, and maximum levels were measured inside subway cars and at several bus stops for comparison purposes. The average noise level measured on the subway platforms was 86 +/- 4 dBA (decibel-A weighting). Maximum levels of 106, 112, and 89 dBA were measured on subway platforms, inside subway cars, and at bus stops, respectively. These results indicate that noise levels in subway and bus stop environments have the potential to exceed recommended exposure guidelines from the World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA), given sufficient exposure duration. Risk reduction strategies following the standard hierarchy of control measures should be applied, where feasible, to reduce subway noise exposure.

Environmental Health↗
PubMed2006

Application of growth-related sublethal endpoints in ecotoxicological assessments using a harpacticoid copepod.

In ecotoxicology, there is an increasing demand for sensitive sublethal endpoints. The primary aim of the present study was therefore to evaluate the relative sensitivity and usefulness of four sublethal endpoints - development time, body length, RNA content and growth rate - in the harpacticoid copepod Nitocra spinipes, using the reference molecule Simvastatin. Development time decreased significantly at low sublethal concentrations of Simvastatin (p < 0.001; F = 13.249; 0.16-1.6 microgL(-1)), while RNA content and body length increased significantly at 0.16 microgL(-1) (p < 0.001; F = 6.13) and 1.6 microgL(-1) (p < 0.01; F = 2.365), respectively. The growth rate increased significantly at 0.16-5 microgL(-1) (p<0.01-0.001). Hence, significant responses of growth-related traits were observed already at 0.16 microgL(-1), which is about 5,000 times lower than the acute toxicity (96 h-LC(50): 810 microgL(-1)). These results show that all assayed endpoints are very sensitive and indicate that current ecotoxicity testing used for environmental protection activities may underestimate the risk for harpacticoid copepods and most likely for other small invertebrates, when relying exclusively on acute toxicity measurements.

Animals↗
PubMed2005

Open-path tunable diode laser absorption spectroscopy for acquisition of fugitive emission flux data.

Air pollutant emission from unconfined sources is an increasingly important environmental issue. The U.S. Environmental Protection Agency (EPA) has developed a ground-based optical remote-sensing method that enables direct measurement of fugitive emission flux from large area sources. Open-path Fourier transform infrared spectroscopy (OP-FTIR) has been the primary technique for acquisition of pollutant concentration data used in this emission measurement method. For a number of environmentally important compounds, such as ammonia and methane, open-path tunable diode laser absorption spectroscopy (OP-TDLAS) is shown to be a viable alternative to Fourier transform spectroscopy for pollutant concentration measurements. Near-IR diode laser spectroscopy systems offer significant operational and cost advantages over Fourier transform instruments enabling more efficient implementation of the measurement strategy. This article reviews the EPA's fugitive emission measurement method and describes its multipath tunable diode laser instrument. Validation testing of the system is discussed. OP-TDLAS versus OP-FTIR correlation testing results for ammonia (R2 = 0.980) and methane (R2 = 0.991) are reported. Two example applications of tunable diode laser-based fugitive emission measurements are presented.

Air Pollutants↗
PubMed2001

Essentials of environmental health. Enhancing your occupational health nursing practice (Part II).

1. In the United States, approximately 24 million people use water daily from unregulated water supplies. Agents of water pollution can be categorized as biological (e.g., Cryptosporidium parvum), chemical (e.g., industrial solvents), or radionuclide (e.g., radon). 2. More than 600 chemicals are registered with the Environmental Protection Agency as pesticides in the United States. Human exposure occurs through direct contact or dermal absorption, inhalation, and ingestion of food, water, and breast milk. It is estimated that 50% of all the pesticides ingested in a lifetime are ingested in the first 5 years of life. 3. Children are at particular risk for exposure to environmental toxicants like pesticides because of time spent crawling and playing on floors, lawns, and other potentially contaminated surface areas, and hand to mouth behaviors. At this time, toxicity data for many pesticides in common use are inadequate to determine potential for neurotoxicity and adverse effects on the developing immune and endocrine system. 4. To meet the challenge of environmental health issues, occupational and environmental health nurses have important opportunities to promote health in the workplace and the community through research, direct clinical services, advocacy, and education.

Environmental Exposure↗
PubMed2003

Optimizing the atmospheric sampling sites using fuzzy mathematic methods.

A new approach applying fuzzy mathematic theorems, including the Primary Matrix Element Theorem and the Fisher Classification Method, was established to solve the optimization problem of atmospheric environmental sampling sites. According to its basis, an application in the optimization of sampling sites in the atmospheric environmental monitoring was discussed. The method was proven to be suitable and effective. The results were admitted and applied by the Environmental Protection Bureau (EPB) of many cities of China. A set of computer software of this approach was also completely compiled and used.

Air Pollutants↗
PubMed2004

Humoral immune factors modulated by copper and chitosan in healthy or parasitised carp (Cyprinus carpio L.) by Ptychobothrium sp. (Cestoda).

As an environmental protection point of view, the potential toxicity of chitosan on aquatic animal health, alone or associated with copper must be investigated. Fish possess defence mechanisms to counteract the impact of toxics. The non-cellular and non-specific immune defences (total immunoglobulin, ceruloplasmin, lysozyme and potential killing activity of phagocytic cells) can be modulated by the potential environmental pollutants but also by natural stimulants such as bacteria, viruses or parasites. In this study, we investigate the potential toxicity of copper (0.1 and 0.25 mg/L) or chitosan (75 and 150 mg/L) and the combination copper and chitosan (0.1 and 75 mg/L, respectively) on two groups of carp: healthy or parasitised by Ptychobothrium sp. Fish exposed to water-soluble chitosan for 96 h had significantly high levels of natural antibodies in plasma. Moreover, activities of lysozyme and ceruloplasmin were also increased in plasma after the same treatment. The exposition of fish to copper have shown apparently contradictory effects on the immune parameters measured but, significant increase of this bacteriolytic activity was observed, particularly in head kidney after 4 days of treatment of fish with copper. The two products may induce separately an acute, short and local inflammatory acute phase response by stimulating some components of the innate immune response of healthy fish. The mixture seems to reduce the impact of the each product due to the physical and chemical properties of chitosan to complex with copper. The responses of humoral immune factors of treated carp was modulated by the presence of the parasite, as shown by the high elevation of lysozyme activity observed in parasitised carps after exposition to copper and by increases in natural antibodies levels observed in parasitised carp treated with the copper-chitosan mixture. This could indicate an additive effect on the stress response mediated by parasite. It occurred a greater stress response in the parasitised group than healthy group exposed to the same treatment evoking an additive effect. So, it is important to specify the health status of organisms to understand responses of immunological markers in fish.

Animals↗
PubMed1988

Chemical scoring system for hazard and exposure identification.

To assist in the preliminary evaluation of compounds of toxicological and environmental interest to the U.S. Environmental Protection Agency (EPA), a scoring system was devised as a collaborative effort between the EPA and the Oak Ridge National Laboratory. The scoring system combines objective guidelines with professional judgment to evaluate chemicals and consists of 11 separate scoring parameters, 6 of which pertain directly to toxicity, e.g., aquatic toxicity and oncogenicity. The remaining parameters are related to environmental fate and occupational, consumer, and environmental exposure. The scoring system was designed to rapidly score chemicals in a minimal amount of time with readily available information. It is used by the Office of Toxic Substances of the EPA as a tool to help set priorities in conjunction with other criteria. It is particularly useful in performing preliminary evaluations involving large chemical classes, such as petroleum distillates.

Environmental Exposure↗
PubMed2006

Measured partitioning coefficients for parent and alkyl polycyclic aromatic hydrocarbons in 114 historically contaminated sediments: part 1. K(OC) values.

Polycyclic aromatic hydrocarbon (PAH) partitioning coefficients between sediment organic carbon and water (K(OC)) values were determined using 114 historically contaminated and background sediments collected from eight different rural and urban waterways in the northeastern United States. More than 2100 individual K(OC) values were measured in quadruplicate for PAHs ranging from two to six rings, along with the first reported K(OC) values for alkyl PAHs included in the U.S. Environmental Protection Agency's (U.S. EPA) sediment narcosis model for the prediction of PAH toxicity to benthic organisms. Sediment PAH concentrations ranged from 0.2 to 8600 microg/g (U.S. EPA 16 parent PAHs), but no observable trends in K(OC) values with concentration were observed for any of the individual PAHs. Literature K(OC) values that are commonly used for environmental modeling are similar to the lowest measured values for a particular PAH, with actual measured values typically ranging up to two orders of magnitude higher for both background and contaminated sediments. For example, the median log K(OC) values we determined for naphthalene, pyrene, and benzo[a]pyrene were 4.3, 5.8, and 6.7, respectively, compared to typical literature K(OC) values for the same PAHs of 2.9, 4.8, and 5.8, respectively. Our results clearly demonstrate that the common practice of using PAH K(OC) values derived from spiked sediments and modeled values based on n-octanol-water coefficients can greatly overestimate the actual partitioning of PAHs into water from field sediments.

Carbon↗
PubMed2002

Development of a Monte Carlo sampling shell for the pesticide root zone model and its application by the Federal Insecticide, Fungicide, and Rodenticide Act Environmental Modeling Validation Task Force.

A user interface to the U.S. Environmental Protection Agency pesticide root zone model (PRZM) was constructed to allow Monte Carlo sampling of input parameter distributions. The interface was constructed employing the Visual Basic for Applications development environment, along with the functionality of the Crystal Ball Professional forecasting and risk analysis package. The tool has been utilized by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Environmental Model Validation Task Force to perform detailed statistical analyses of model input parameter uncertainty and the propagation of this uncertainty on the model outputs as well as comparisons of modeled and field-measured data.

Environment↗
PubMed2006

Assessing and managing methylmercury risks associated with power plant mercury emissions in the United States.

Until the Clean Air Mercury Rule was signed in March 2005, coal-fired electric utilities were the only remaining, unregulated major source of industrial mercury emissions in the United States. Proponents of coal-burning power plants assert that methylmercury is not a hazard at the current environmental levels, that current technologies for limiting emissions are unreliable, and that reducing mercury emissions from power plants in the United States will have little impact on environmental levels. Opponents of coal-burning plants assert that current methylmercury exposures from fish are damaging to the developing nervous system of infants, children, and the fetus; that current technology can significantly limit emissions; and that reducing emissions will reduce exposure and risk. One concern is that local mercury emissions from power plants may contribute to higher local exposure levels, or "hot spots." The impact of the Mercury Rule on potential hot spots is uncertain due to the highly site-specific nature of the relationship between plant emissions and local fish methylmercury levels. The impact on the primary source of exposure in the United States, ocean fish, is likely to be negligible due to the contribution of natural sources and industrial sources outside the United States. Another debate centers on the toxic potency of methylmercury, with the scientific basis of the US Environmental Protection Agency's (EPA's) recommended exposure limit questioned by some and defended by others. It is likely that the EPA's exposure limit may be appropriate for combined exposure to methylmercury and polychlorinated biphenyls (PCBs), but may be lower than the available data suggest is necessary to protect children from methylmercury alone. Mercury emissions from power plants are a global problem. Without a global approach to developing and implementing clean coal technologies, limiting US power plant emissions alone will have little impact.

Air Pollution↗
PubMed1995

Chemical mixtures: current risk assessment methodologies and future directions.

Some of the most challenging problems that toxicologists confront are determining how biological effects of components in a complex mixture may interact, determining how these interactions affect the overall toxicity of the mixture, and determining how to incorporate this information into risk assessments of chemical mixtures. There has been considerable effort in this area since the publication of the U.S. Environmental Protection Agency's guidelines for risk assessment of chemical mixtures in 1986. This paper reviews the terminology used to describe chemical interactions and the methodologies that have been developed for conducting risk assessments of chemical mixtures. Particular attention is directed towards an examination of the applicability and validity of the methods for the assessment of risk posed by exposure to environmentally relevant concentrations of chemical mixtures. Limited, yet compelling, data are reviewed that suggest that for noncancer endpoints, adverse effects are unlikely to occur when the individual components in the mixture are present at levels well below their respective thresholds. Synergistic or antagonistic effects, not readily predicted from the mechanisms of action of the individual components, are possible when the mixture components are present at levels equal to or above their individual thresholds. Finally, synergistic carcinogenic effects have been observed in animal studies of mixtures, even at relatively low doses.

Animals↗
PubMed2002

Advances in the determination of inorganic ions in potable waters by ion chromatography.

Ion chromatography (IC) is now a well-established methodology for the analysis of ionic species. The technique is applicable to the determination of a wide range of solutes in many sample types, although the determination of inorganic ions in potable waters continues to be the most widely used application of ion chromatography. Many standardization and regulatory bodies, such as the American Society for Testing and Materials (ASTM), International Organization for Standardization (ISO), and US Environmental Protection Agency (EPA), have approved methods of analysis based upon IC, most of which have been published within the last decade. Recent developments in the field of IC, such as the use of higher capacity columns, larger loop injections, more complex sample preparation and detection schemes, have been incorporated into these new approved methods. These advances allow the determination of environmentally significant contaminants, such as common inorganic anions, bromate, perchlorate and chromate, at trace levels in potable waters using ion chromatography.

Chromatography, Ion Exchange↗
PubMed2002

Effects of engine speed and accessory load on idling emissions from heavy-duty diesel truck engines.

A nontrivial portion of heavy-duty vehicle emissions of NOx and particulate matter (PM) occurs during idling. Regulators and the environmental community are interested in curtailing truck idling emissions, but current emissions models do not characterize them accurately, and little quantitative data exist to evaluate the relative effectiveness of various policies. The objectives of this study were to quantify the effect of accessory loading and engine speed on idling emissions from a properly functioning, modern, heavy-duty diesel truck and to compare these results with data from earlier model year vehicles. It was found that emissions during idling varied greatly as a function of engine model year, engine speed, and accessory load conditions. For the 1999 model year Class 8 truck tested, raising the engine speed from 600 to 1050 rpm and turning on the air conditioning resulted in a 2.5-fold increase in NOx emissions in grams per hour, a 2-fold increase in CO2 emissions, and a 5-fold increase in CO emissions while idling. On a grams per gallon fuel basis, NOx emissions while idling were approximately twice as high as those at 55 mph. The CO2 emissions at the two conditions were closer. The NOx emissions from the 1999 truck while idling with air conditioning running were slightly more than those of two 1990 model year trucks under equivalent conditions, and the hydrocarbon (HC) and CO emissions were significantly lower. It was found that the NOx emissions used in the California Air Resources Board's (CARB) EMFAC2000 and the U.S. Environmental Protection Agency's (EPA) MOBILE5b emissions inventory models were lower than those measured in all of the idling conditions tested on the 1999 truck.

Engineering↗
PubMed2002

Apartment residents' and day care workers' exposures to tetrachloroethylene and deficits in visual contrast sensitivity.

Tetrachloroethylene (also called perchloroethylene, or perc), a volatile organic compound, has been the predominant solvent used by the dry-cleaning industry for many years. The U.S. Environmental Protection Agency (EPA) classified perc as a hazardous air pollutant because of its potential adverse impact on human health. Several occupational studies have indicated that chronic, airborne perc exposure adversely affects neurobehavioral functions in workers, particularly visual color discrimination and tasks dependent on rapid visual-information processing. A 1995 study by Altmann and colleagues extended these findings, indicating that environmental perc exposure at a mean level of 4,980 microg/m(3) (median=1,360 microg/m(3)) alters neurobehavioral functions in residents living near dry-cleaning facilities. Although the U.S. EPA has not yet set a reference concentration guideline level for environmental exposure to airborne perc, the New York State Department of Health set an air quality guideline of 100 microg/m(3). In the current residential study, we investigated the potential for perc exposure and neurologic effects, using a battery of visual-system function tests, among healthy members of six families living in two apartment buildings in New York City that contained dry-cleaning facilities on the ground floors. In addition, a day care investigation assessed the potential for perc exposure and effects among workers at a day care center located in the same one-story building as a dry-cleaning facility. Results from the residential study showed a mean exposure level of 778 microg/m(3) perc in indoor air for a mean of 5.8 years, and that perc levels in breath, blood, and urine were 1-2 orders of magnitude in excess of background values. Group-mean visual contrast sensitivity (VCS), a measure of the ability to detect visual patterns, was significantly reduced in the 17 exposed study participants relative to unexposed matched-control participants. The groups did not differ in visual acuity, suggesting that the VCS deficit was of neurologic origin. Healthy workers in the day care investigation were chronically exposed to airborne perc at a mean of 2,150 microg/m(3) for a mean of 4.0 years. Again, group-mean VCS, measured 6 weeks after exposure cessation, was significantly reduced in the nine exposed workers relative to matched controls, and the groups did not differ significantly in visual acuity. These results suggested that chronic, environmental exposure to airborne perc adversely affects neurobehavioral function in healthy individuals. Further research is needed to assess the susceptibility of the young and elderly to perc-induced effects, to determine whether persistent solvent-induced VCS deficits are a risk factor for the development of neurologic disease, and to identify the no observable adverse effect level for chronic, environmental, perc exposure in humans.

Adolescent↗
PubMed1981

Dibromochloropropane (DBCP): a review.

A highly persistent, lipophilic, brominated organochlorine which is effectively used against nematodes, dibromochloropropane (DBCP) has been produced for agriculture since 1955. In 1975, production of DBCP in the United States reached 25 million lbs. However, investigations with laboratory animals, some of which were published in the early 1960s, have shown that DBCP decreases sperm mobility and spermatogenesis, disturbs the estrous cycle, reduces phagocytosis by white blood cells, and induces malignant tumors. Later studies with procaryotic and eucaryotic cells, including human sperm, have demonstrated DBCP to be mutagenic and to effect the genome adversely. In 1977 many of the employees at the Occidental Chemical plant in Lathrop, California, who had handled DBCP, were found to be either azoospermic or oligospermic. Subsequent surveys of employees handling DBCP at other chemical plants confirmed these findings. In 1977 on edible crops and in 1979 DBCP per se was detected in well waters. As a result of these studies, the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA) in 1977 promulgated regulations restricting the use and handling of DBCP. In 1979, the EPA banned almost all agricultural uses of DBCP.

Animals↗
PubMed1997

A multiyear workplace-monitoring program for refractory ceramic fibers: findings and conclusions.

Results of a monitoring program carried out by members of the Refractory Ceramic Fibers Coalition as part of a Consent Agreement with the U.S. Environmental Protection Agency to measure workplace concentrations of refractory ceramic fiber (RCF) are presented. More than 700 personal monitoring samples were collected and analyzed annually from workers in RCF production and processing plants, as well as from those employed by customers/end users. The data indicate that (i) approximately 90% of time-weighted average (TWA) workplace concentrations are below the industry's recommended exposure guideline of 1 fiber per cubic centimeter TWA; (ii) workplace concentrations vary with functional job category; (iii) concentrations are approximately lognormally distributed; (iv) workplace concentrations are generally decreasing; (v) there are significant differences in workplace concentrations among plants operated by both RCF producers and customers; (vi) equations can be developed to interconvert data analyzed using different measurement techniques and counting rules; (vii) usage of respirators varies with the functional job category of the worker and the average fiber concentration; and (viii) workplace samples differ from those used in animal inhalation experiments in terms of the ratio of respirable particles to fibers.

Ceramics↗
PubMed1993

Analysis of 222Rn concentration in North Carolina household water supplies derived from private wells.

The objectives of this study were to characterize the concentrations of 222Rn in North Carolina household groundwater supplies and to investigate the relationship between indoor air and groundwater 222Rn concentrations. Measurements of 222Rn in groundwater supplies were performed in 400 North Carolina homes in which a state/Environmental Protection Agency survey had made measurements of indoor airborne 222Rn. The arithmetic mean 222Rn concentration measured in groundwater supplies statewide was 67 Bq L-1 (1,800 pCi L-1), and the geometric mean was 24 Bq L-1 (660 pCi L-1). Sixty-seven percent of the state's homes with wells had 222Rn water concentrations in excess of the Environmental Protection Agency's proposed limit for public drinking water supplies of 11 Bq L-1 (300 pCi L-1). The percentage of homes with water concentrations in excess of the proposed limit was 30% in the eastern region of the state, 75% in the central region, and 83% in the western region. No significant correlation was observed between measurements of indoor air and water 222Rn concentrations in these homes.

Air Pollution, Indoor↗
PubMed1994

Adverse environmental conditions in the respiratory and medical ICU settings.

Sleep deprivation and fragmentation occurring in the hospital setting may have a negative impact on the respiratory system by decreasing respiratory muscle function and ventilatory response to CO2. Sleep deprivation in a patient with respiratory failure may, therefore, impair recovery and weaning from mechanical ventilation. We postulate that light, sound, and interruption levels in a weaning unit are major factors resulting in sleep disorders and possibly circadian rhythm disruption. As an initial test of this hypothesis, we sampled interruption levels and continuously monitored light and sound levels for a minimum of seven consecutive days in a medical ICU, a multiple bed respiratory care unit (RCU) room, a single-bed RCU room, and a private room. Light levels in all areas maintained a day-night rhythm, with peak levels dependent on window orientation and shading. Peak sound levels were extremely high in all areas representing values significantly higher than those recommended by the Environmental Protection Agency as acceptable for a hospital environment. The number of sound peaks greater than 80 decibels, which may result in sleep arousals, was especially high in the intensive and respiratory care areas, but did show a day-night rhythm in all settings. Patient interruptions tended to be erratic, leaving little time for condensed sleep. We conclude that the potential for environmentally induced sleep disruption is high in all areas, but especially high in the intensive and respiratory care areas where the negative consequences may be the most severe.

Circadian Rhythm↗