Circulating levels of environmental contaminants are associated with dietary patterns in older adults

BackgroundFood intake contributes substantially to our exposure to environmental contaminants. Still, little is known about our dietary habits' contribution to exposure variability.ObjectiveThe aim of this study was to assess circulating levels of environmental contaminants in relation to predefined dietary patterns in an elderly Swedish population.MethodsDietary data and serum concentrations of environmental contaminants were obtained from 844 70-year-old Swedish subjects (50% women) in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. Dietary data from 7-day food records was used to assess adherence to a Mediterranean-like diet, a low carbohydrate–high protein diet and the WHO dietary recommendations. Circulating levels of 6 polychlorinated biphenyl markers, 3 organochlorine pesticides, 1 dioxin and 1 polybrominated diphenyl ether, the metals cadmium, lead, mercury and aluminum and serum levels of bisphenol A and 4 phthalate metabolites were investigated in relation to dietary patterns in multivariate linear regression models.ResultsA Mediterranean-like diet was positively associated with levels of several polychlorinated biphenyls (118, 126, 153, and 209), trans-nonachlor and mercury. A low carbohydrate–high protein diet was positively associated with polychlorinated biphenyls 118 and 153, trans-nonachlor, hexachlorobenzene and p, p′-dichlorodiphenyldichloroethylene, mercury and lead. The WHO recommended diet was negatively related to levels of dioxin and lead, and borderline positively to polychlorinated biphenyl 118 and trans-nonachlor.ConclusionDietary patterns were associated in diverse manners with circulating levels of environmental contaminants in this elderly Swedish population. Following the WHO dietary recommendations seems to be associated with a lower burden of environmental contaminants.     

Annual and diurnal variations of gaseous and particulate pollutants in 31 provincial capital cities based on in situ air quality monitoring data from China National Environmental Monitoring Center

Long-term air quality data with high temporal and spatial resolutions are needed to understand some important processes affecting the air quality and corresponding environmental and health effects. The annual and diurnal variations of each criteria pollutant including PM_2.5 and PM₁₀ (particulate matter with aerodynamic diameter less than 2.5 μm and 10 μm, respectively), CO (carbon monoxide), NO₂ (nitrogen dioxide), SO₂ (sulfur dioxide) and O₃ (ozone) in 31 provincial capital cities between April 2014 and March 2015 were investigated by cluster analysis to evaluate current air pollution situations in China, and the cities were classified as severely, moderately, and slightly polluted cities according to the variations. The concentrations of air pollutants in winter months were significantly higher than those in other months with the exception of O₃, and the cities with the highest CO and SO₂ concentrations were located in northern China. The annual variation of PM_2.5 concentrations in northern cities was bimodal with comparable peaks in October 2014 and January 2015, while that in southern China was unobvious with slightly high PM_2.5 concentrations in winter months. The concentrations of particulate matter and trace gases from primary emissions (SO₂ and CO) and NO₂ were low in the afternoon (~ 16:00), while diurnal variation of O₃ concentrations was opposite to that of other pollutants with the highest values in the afternoon. The most polluted cities were mainly located in North China Plain, while slightly polluted cities mostly focus on southern China and the cities with high altitude such as Lasa. This study provides a basis for the formulation of future urban air pollution control measures in China.     

An analysis of the environmental pressure exerted by the eucalyptus-based kraft pulp industry in Thailand

The study reported here focuses on the environmental pressure exerted by large-scale eucalyptus-based kraft pulp industry in Thailand. The objective of this study was to identify the most important sources of greenhouse gases, acidifying and eutrophying compounds and tropospheric ozone precursors, human toxicity compounds and solid waste associated with the kraft pulp industry. To this end, we performed an environmental systems analysis of the kraft pulp industry system in which we distinguished between two subsystems: the eucalyptus forestry subsystem and the kraft pulp production subsystem. The results indicate that the environmental pressure is caused by the kraft pulp production subsystem rather than by the eucalyptus forestry one. The chemical recovery unit was found to be the most important source of carbon dioxide (CO₂) and sulfur dioxide (SO₂) and responsible for more than one-half of the emissions of greenhouse gases and acidifying compounds from eucalyptus-based kraft pulp production in Thailand. Biomass combustion in the energy gene ration unit is an important source of nitrogen oxide (NO _x ) and carbon monoxide (CO) which in turn are responsible for over 50% of the emissions of tropospheric ozone precursors. About 73% of the eutrophication is caused by biological aerobic wastewater treatment emitting phosphorus (P). With respect to the eucalyptus forestry, only fertilizer use in eucalyptus plantations is a relevant source of pollution through the emission of nitrous oxide (N₂O) and phosphate (PO ₄ ³⁻ ).     

Tritium concentrations in the atmospheric environment at Rokkasho, Japan before the final testing of the spent nuclear fuel reprocessing plant

This study aimed at obtaining background tritium concentrations in precipitation and air at Rokkasho where the first commercial spent nuclear fuel reprocessing plant in Japan has been under construction. Tritium concentration in monthly precipitation during fiscal years 2001-2005 had a seasonal variation pattern which was high in spring and low in summer. The tritium concentration was higher than that observed at Chiba City as a whole. The seasonal peak concentration at Rokkasho was generally higher than that at Chiba City, while the baseline concentrations of both were similar. The reason for the difference may be the effect of air mass from the Asian continent which is considered to have high tritium concentration. Atmospheric tritium was operationally separated into HTO, HT and hydrocarbon (CH₃T) fractions, and the samples collected every 3 d-14 d during fiscal year 2005 were analyzed for these fractions. The HTO concentration as radioactivity in water correlated well with that in the precipitation samples. The HT concentration was the highest among the chemical forms analyzed, followed by the HTO and CH₃T concentrations. The HT and CH₃T concentrations did not have clear seasonal variation patterns. The HT concentration followed the decline previously reported by Mason and Östlund with an apparent half-life of 4.8 y. The apparent and environmental half-lives of CH₃T were estimated as 9.2 y and 36.5 y, respectively, by combining the present data with literature data. The Intergovernmental Panel on Climate Change used the atmospheric lifetime of 12 y for CH₄ to estimate global warming in its 2007 report. The longer environmental half-life of CH₃T suggested its supply from other sources than past nuclear weapon testing in the atmosphere.     

Review of pollutants in petroleum refinery wastewaters and effect upon aquatic organisms

In the past decade, the number of organic chemical contaminants identified in oil refinery wastewaters has risen from less than 20 to over 300. This increase in knowledge was made possible by advances in gas chromatography-mass spectrometry instrumentation and new techniques to maximize resolution of capillary chromatography. The types of compounds identified in refinery wastewaters are similar to those identified in crude oils; i.e., aliphatic, aromatic, alkyl aromatic, polynuclear aromatic hydrocarbons, and some hydrocarbons containing nitrogen, sulfur, and oxygen. The contaminants in oil refinery wastewaters acutely lethal to aquatic organisms can be removed by biological treatment systems. However, biological treatment systems may not be capable of removing all deleterious contaminants. Long-term fathead minnow bioassays of biologically treated refinery wastewaters resulted in 10%–50% mortality after 14–16 days of exposure. The lethal effects were eliminated by sequential treatment with dual media filtration-activated carbon adsorption.     

A test of environmental Kuznets curve (EKC) for carbon emission and potential of renewable energy to reduce green house gases (GHG) in Malaysia

This study investigates the presence of environmental kuznets curve (EKC) for green house gases (GHG) measured by CO₂ emission in Malaysia for the period 1970 to 2011. The study also examines the potential of the renewable source of energy to contain GHG. The long-run significant positive coefficient of GDP indicates that the GHG are increasing with economic growth while the insignificant coefficient on GDP square rejects the EKC transition. These results indicate a high GDP level for the EKC turning point for Malaysia. Therefore, it can be stated that only economic growth cannot reverse the environmental degradation in Malaysia. The government should have to come up with some policy measures to achieve CO₂ emission reduction targets that Malaysia has pledged to achieve in Paris Submit (2015). The renewable energy production is found to have significant negative effect on CO₂ emission. So government should focus on the renewable source of energy production and should frame a special policy for renewable energy production.     

An environmental wide association study (EWAS) approach to the metabolic syndrome

BackgroundEnvironmental contaminants have previously been linked to components of the Metabolic Syndrome (MetS). However, exposure to environmental contaminants is in part determined by various lifestyle factors.ObjectiveUsing an “Environmental Wide Association Study” (ELWAS) integrating environmental contaminants and lifestyle factors, we aimed to evaluate a possible additive role of both contaminants and lifestyle factors regarding MetS.Methods1016 subjects aged 70 years were investigated in the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. 43 environmental contaminants were measured in the circulation. Dietary records were used to evaluate 21 nutrients and the proportions of 13 fatty acids were determined in serum cholesterol esters to further quantify fat quality intake. Adding 5 other important lifestyle factors yielded together 76 environmental and lifestyle factors. MetS was defined by the NCEP/ATPIII-criteria.Results23% had MetS. Using cross-validation within the sample, fourteen environmental contaminants or lifestyle factors consistently showed a false discovery rate < 0.05. When the major variables entered a multiple model, only p, p′-DDE levels (positive), PCB209 (inverse) and exercise habits (inverse) were together with a fatty acid pattern, with high levels of palmitic acid and oleic acid and low levels of linoleic acid, related to MetS (p < 0.002 for all variables).ConclusionUsing a cross-sectional EWAS approach, certain environmental contaminants and lifestyle factors were found to be associated with prevalent metabolic syndrome in an additive fashion in an elderly population.     

The influence of ventilation on indoor/outdoor air contaminants in an office building

The air quality in a newly built preschool was investigated in a longitudinal study. Typical air contaminants emanating from building materials were determined, their variation over time (0–18 months) was measured, and the influence of the ventilation system (81%–91% recirculation of return air) on contaminant concentrations was studied. Volatile organic compounds were sampled by adsorption on porous polymer, analysed by a GC/FID system, and identified by MS. A spatial build-up in concentration (ppb or μg/m³ levels) is evident for all the organic compounds, as well as for CO₂, from the outdoor air, through the ventilation system, and through the rooms to the exhaust air. The longitudinal comparison over time shows that all the organic compounds decline in concentration mainly within the first 6 months of occupancy: 1-butanol 4–14 times, toluene and pentanal + hexanal 2–4 times, while formaldehyde remained at a constant low level of 90 ppb (110 μg/m³). It is difficult to believe that the problems of poor air quality in 100 preschools in Stockholm are caused by the organic compounds alone unless interactions occur. A preschool building needs to be gassed off during the first 6 months after its construction with no recirculation of return air allowed (outdoor air rate approx 4–5 ach). During at least 1–2 additional years, it is desired that the recirculation rate of return air is restricted, perhaps to 50%.     

Concentrations of polybrominated diphenyl ethers (PBDEs) and 2,4,6-tribromophenol in human placental tissues

Legacy environmental contaminants such as polybrominated diphenyl ethers (PBDEs) are widely detected in human tissues. However, few studies have measured PBDEs in placental tissues, and there are no reported measurements of 2,4,6-tribromophenol (2,4,6-TBP) in placental tissues. Measurements of these contaminants are important for understanding potential fetal exposures, as these compounds have been shown to alter thyroid hormone regulation in vitro and in vivo. In this study, we measured a suite of PBDEs and 2,4,6-TBP in 102 human placental tissues collected between 2010 and 2011 in Durham County, North Carolina, USA. The most abundant PBDE congener detected was BDE-47, with a mean concentration of 5.09 ng/g lipid (range: 0.12–141 ng/g lipid; detection frequency 91%); however, 2,4,6-TBP was ubiquitously detected and present at higher concentrations with a mean concentration of 15.4 ng/g lipid (range:1.31–316 ng/g lipid; detection frequency 100%). BDE-209 was also detected in more than 50% of the samples, and was significantly associated with 2,4,6-TBP in placental tissues, suggesting they may have a similar source, or that 2,4,6-TBP may be a degradation product of BDE-209. Interestingly, BDE-209 and 2,4,6-TBP were negatively associated with age (r_s = − 0.16; p = 0.10 and r_s = − 0.17; p = 0.08, respectively). The results of this work indicate that PBDEs and 2,4,6-TBP bioaccumulate in human placenta tissue and likely contribute to prenatal exposures to these environmental contaminants. Future studies are needed to determine if these joint exposures are associated with any adverse health measures in infants and children.     

The potential impact of environmental variation on the concentrations and ecological effects of pollutants in a marine avian top predator

Concentrations of organochlorine contaminants (OCs) and associations between OCs and fitness components were examined in great black-backed gulls (Larus marinus) in three colonies along the coast of northern Norway. In one of the colonies, data were collected in two subsequent seasons. Concentrations of four OCs (HCB, oxychlordane, DDE and PCB) were measured in blood (n=260) and fitness components (reproductive variables and adult return rate between breeding seasons) were recorded. In the first year, in two of the colonies, body condition and reproductive performance among the gulls were poor compared to the third colony, suggesting spatial variation in environmental conditions, especially food availability. However, in the third colony, body condition and reproductive performance were even better in the second season; i.e. environmental conditions varied temporally. OC residues were higher in the colonies where environmental conditions were poor, but much of this variation was explained by differences in body condition among colonies. Moreover, concurrent with improved body condition from one season to the next, the concentrations of OCs were halved. In the two colonies where environmental conditions were poor, female OC residues were negatively related to egg-laying date, egg size and nesting success, and in the colony where the concentrations of OC were highest, gulls with elevated DDE residues had low probability of returning between breeding seasons. In comparison, in the colony where environmental conditions were better in the first year, other types of adverse relationships between OCs and fitness components were found; i.e. chicks from females with high OC concentrations were in poor condition at hatching, suggesting maternal transfer of OCs to the eggs, and males with high OC residues had poor nesting success and chick survival, suggesting OC-mediated behavioural changes. With improved environmental conditions and lower OC concentrations in the second season, no significant adverse relationships between OCs and fitness components were found. This study thus suggests that there are complex interrelationships between both concentrations and ecological effects of OCs, and the environment, indicating that effects of OCs in nature may only be assessed after considering environmental variation.     

Factors affecting 210Po and 210Pb activity concentrations in mussels and implications for environmental bio-monitoring programmes

The activity of ²¹⁰Po and ²¹⁰Pb was determined in mussels of the same size (3.5-4.0 cm shell length) sampled monthly over a 17-month period at the Atlantic coast of Portugal. Average radionuclide concentration values in mussels were 759 ± 277 Bq kg⁻¹ for ²¹⁰Po (range 460-1470 Bq kg⁻¹ dry weight), and 45 ± 19 Bq kg⁻¹ for ²¹⁰Pb (range 23-96 Bq kg⁻¹ dry weight). Environmental parameters and mussel biometric parameters were monitored during the same period. Although there was no seasonal variation of radionuclide concentrations in sea water during the study period, the concentration of radionuclide activity in mussels varied seasonally displaying peaks of high concentrations in winter and low concentrations in summer. Analysis of radionuclide data in relation to the physiological Condition Index of mussels revealed that ²¹⁰Po and ²¹⁰Pb activities in the mussel (average activity per individual) remained nearly constant during the investigation period, while mussel body weight fluctuated due to fat storage/expenditure in the soft tissues. Similar variation of radionuclide concentrations was observed in mussels transplanted from the sea coast into the Tejo Estuary. However, under estuarine environmental conditions and with higher food availability throughout the year, transplanted mussel Condition Index was higher than in coastal mussels and average radionuclide concentrations were 210 ± 75 Bq kg⁻¹ (dry weight) for ²¹⁰Po and 10 ± 4 Bq kg⁻¹ (dry weight) for ²¹⁰Pb, therefore lower than in coastal mussels with similar shell length. It is concluded that the apparent seasonal fluctuation and inter-site difference of radionuclide concentrations were mostly caused by mussel body weight fluctuation and not by radionuclide body burden fluctuation. This interpretation can be extended to the apparent seasonal fluctuation in concentrations of lipophilic and lipophobic contaminants in mussels, and provides an explanation for occasional high concentrations of ²¹⁰Po and man-made contaminants measured in mussels far from pollution sources.     

Changes in concentrations of hydrophilic organic contaminants and of endocrine-disrupting potential downstream of small communities located adjacent to headwaters

Endocrine-disruptive potential and concentrations of polar organic contaminants were measured in seven headwaters flowing through relatively unpolluted areas of the Czech Republic. Towns with Wastewater Treatment Plant (WWTP) discharges were the first known sources of anthropogenic pollution in the areas. River water was sampled several kilometers upstream (US) and several tens of meters downstream (DS) of the WWTP discharges, by use of Pesticide and Pharmaceutical Polar Organic Integrative Samplers (POCIS-Pest, POCIS-Pharm). Extracts of passive samplers were tested by use of a battery of in vitro bioassays to determine overall non-specific cytotoxicity, endocrine-disruptive (ED) potential and dioxin-like toxicity. The extracts were also used for quantification of polar organics. There was little toxicity to cells caused by most extracts of POCIS. Estrogenicity was detected in all types of samples even though US locations are considered to be background. At US locations, concentrations of estrogen equivalents (EEq) ranged from less than the detection limits (LOD) to 0.5 ng EEq/POCIS. Downstream concentrations of EEqs ranged from less than LOD to 4.8 ng EEq/POCIS. Concentrations of EEq in POCIS extracts from all DS locations were 1 to 14 times greater than those at US locations. Concentrations of EEq measured in extracts of POCIS-Pest and POCIS-Pharm were in a good agreement. Neither antiestrogenic nor anti/androgenic activities were detected. Concentrations of 2,3,7,8-TCDD equivalents (TEq_bio) were detected in both types of POCIS at concentrations ranging from less than the LOD to 0.39 ng TEq_bio/POCIS. Nearly all extracts of POCIS-Pharm contained greater concentrations of TEq_bio activity than extracts of POCIS-Pest. Concentrations of pesticides and pharmaceuticals in extracts of POCIS were generally small at all sampling sites, but levels of some pharmaceuticals were significantly greater in both types of POCIS from DS locations. Chemical analyses along with the results of bioassays documented impacts of small towns with WWTPs on headwaters.     

Predictors of PCP,OH-PCBs,PCBs and chlorinated pesticides in a general female Norwegian population

The aims of the current study were to assess plasma concentrations and predictors of halogenated phenolic compounds (HPCs), polychlorinated biphenyls (PCBs) and chlorinated pesticides in a representative group of postmenopausal Norwegian women (n = 311, mean age: 56 years). In addition to delivering a blood sample, the participants had also filled out a detailed questionnaire regarding their current health status, use of medication and dietary habits, etc. The association between a large number of dietary variables, lifestyle factors and plasma concentration of organic pollutants were investigated using multivariate statistics.Within the current study group, p,p′-DDE (median: 903 ng/L w.w.) and pentachlorophenol (PCP, median: 711 ng/L w.w.) were the dominating compounds on a wet weight basis and were present in considerable higher concentrations than the PCBs, the hydroxylated PCBs (OH-PCBs) and the remaining chlorinated pesticides. Of the PCBs, PCB 153 was detected in highest concentrations, whereas 4-OH-PCB187 was present in highest concentration of the selected OH-PCBs. The ratio of ΣOH-PCB to ΣPCB varied between 0.06 and 0.77 ng/L and were significantly lower in individuals with higher ΣPCB concentration. PCP did not co-vary with the other contaminants, indicating a different route of exposure. No clear food cluster was positively associated with PCP exposure; however intake of marine food was negatively linked to PCP concentration and age and being a non-smoker were positive predictors of PCP. The other investigated contaminants co-varied and were positively associated with age, plasma concentrations of marine derived omega-3 fatty acids and a traditional Norwegian fish and bread based diet. The difference in contaminant concentration between high, medium and low consumers of total marine food were however marginal for the dominating PCBs and chlorinated pesticides. The current results indicate however that marine food in itself could be a source of some of the OH-PCBs, regardless of their PCB precursors.As PCP is one of the dominating organic contaminants within the general female Norwegian population, future research on human concentrations, exposure routes and potential health effects of PCP is encouraged. Continued monitoring of human OH-PCB levels should also be performed as they could be present at levels almost as high as the PCBs and they are expected to be more toxic than their mother substances.     

Movement towards a low carbon emitted environment: a test of some factors in Malaysia

There exists a high global concern in different nations on environmental sustainability especially at the focal stage of increased economic growth and development process due to high level of environmental degradation and pollution. The major aim of this study was to empirically examine how to minimise carbon emissions (CO₂) in Malaysia which are mainly caused by energy production, fossil fuel consumption, population density and economic growth. The study adopted the method of autoregressive distributed lag bound testing approach to analyse the data for the period 1971–2011. The study found that economic growth in Malaysia has a direct relationship with CO₂ emissions in both the short run and the long run. Similarly, there is a positive relationship between fossil fuel consumption and CO₂ emissions over the same period. Population density was found to have positive impacts on CO₂ emissions. Contrarily, the relationship between the activities of energy production and pollution is negative in the long run. The study recommends that a targeted GDP growth rate should be set with the consideration to avoid more environmental pollution. In addition, the positive impact of fossil fuel consumption on the environmental pollution implies that there is a need to make and implement policies that will encourage the use of public transportation system more than private transportations. That is, the unnecessary use of private vehicles should be discouraged in order to reduce the extent of fossil fuel consumption.     

Estrogen-, androgen- and aryl hydrocarbon receptor mediated activities in passive and composite samples from municipal waste and surface waters

Passive and composite sampling in combination with in vitro bioassays and identification and quantification of individual chemicals were applied to characterize pollution by compounds with several specific modes of action in urban area in the basin of two rivers, with 400,000 inhabitants and a variety of industrial activities. Two types of passive samplers, semipermeable membrane devices (SPMD) for hydrophobic contaminants and polar organic chemical integrative samplers (POCIS) for polar compounds such as pesticides and pharmaceuticals, were used to sample wastewater treatment plant (WWTP) influent and effluent as well as rivers upstream and downstream of the urban complex and the WWTP. Compounds with endocrine disruptive potency were detected in river water and WWTP influent and effluent. Year-round, monthly assessment of waste waters by bioassays documented estrogenic, androgenic and dioxin-like potency as well as cytotoxicity in influent waters of the WWTP and allowed characterization of seasonal variability of these biological potentials in waste waters. The WWTP effectively removed cytotoxic compounds, xenoestrogens and xenoandrogens. There was significant variability in treatment efficiency of dioxin-like potency. The study indicates that the WWTP, despite its up-to-date technology, can contribute endocrine disrupting compounds to the river. Riverine samples exhibited dioxin-like, antiestrogenic and antiandrogenic potencies. The study design enabled characterization of effects of the urban complex and the WWTP on the river. Concentrations of PAHs and contaminants and specific biological potencies sampled by POCIS decreased as a function of distance from the city.     

Chemical contaminants in swimming pools: Occurrence,implications and control

A range of trace chemical contaminants have been reported to occur in swimming pools. Current disinfection practices and monitoring of swimming pool water quality are aimed at preventing the spread of microbial infections and diseases. However, disinfection by-products (DBPs) are formed when the disinfectants used react with organic and inorganic matter in the pool. Additional chemicals may be present in swimming pools originating from anthropogenic sources (bodily excretions, lotions, cosmetics, etc.) or from the source water used where trace chemicals may already be present. DBPs have been the most widely investigated trace chemical contaminants, including trihalomethanes (THMs), haloacetic acids (HAAs), halobenzoquinones (HBQs), haloacetonitriles (HANs), halonitromethanes (HNMs), N-nitrosamines, nitrite, nitrates and chloramines. The presence and concentrations of these chemical contaminants are dependent upon several factors including the types of pools, types of disinfectants used, disinfectant dosages, bather loads, temperature and pH of swimming pool waters. Chemical constituents of personal care products (PCPs) such as parabens and ultraviolet (UV) filters from sunscreens have also been reported. By-products from reactions of these chemicals with disinfectants and UV irradiation have been reported and some may be more toxic than their parent compounds. There is evidence to suggest that exposure to some of these chemicals may lead to health risks. This paper provides a detailed review of various chemical contaminants reported in swimming pools. The concentrations of chemicals present in swimming pools may also provide an alternative indicator to swimming pool water quality, providing insights to contamination sources. Alternative treatment methods such as activated carbon filtration and advanced oxidation processes may be beneficial in improving swimming pool water quality.     

Spatial variations in the associations of term birth weight with ambient air pollution in Georgia,USA

Birth weight is an important indicator of overall infant health and a strong predictor of infant morbidity and mortality, and low birth weight (LBW) is a leading cause of infant mortality in the United States. Numerous studies have examined the associations of birth weight with ambient air pollution, but the results were inconsistent. In this study, a spatial statistical technique, geographically weighted regression (GWR) is applied to explore the spatial variations in the associations of birth weight with concentrations of ozone (O₃) and fine particulate matter (PM_2.5) in the State of Georgia, USA adjusted for gestational age, parity, and six other socioeconomic, behavioral, and land use factors. The results show considerable spatial variations in the associations of birth weight with both pollutants. Significant positive, non-significant, and significant negative relationships between birth weight and concentrations of each air pollutant are all found in different parts of the study area, and the different types of the relationships are affected by the socioeconomic and urban characteristics of the communities where the births are located. The significant negative relationships between birth weight and O₃ indicate that O₃ is a significant risk factor of LBW and these associations are primarily located in less-urbanized communities. On the other hand, PM_2.5 is a significant risk factor of LBW in the more-urbanized communities with higher family income and education attainment. These findings suggest that environmental and health policies should be adjusted to address the different effects of air pollutants on birth outcomes across different types of communities to more effectively and efficiently improve birth outcomes.     

Environmental significance of nitrogenous organic compounds in aquatic sources

The presence of nitrogenous organic compounds in raw water sources for municipal supplies is of environmental concern because many of them exert significant chlorine demand, while some produce complex stable mutagenic products upon chlorination or are precursors to haloform formation. Seven N-organic compounds have been identified in municipal water concentrates (adenine, 5-chlorouracil, cytosine, guanine, purine, thymine, and uracil) at concentrations ranging from 20 to 860 μg/L. Eight compounds (adenine, cytosine, purine, pyrrole, thymine, tryptophan, tyrosine, and uracil) have been found in filtrates from cultures of either Anabaena flos aquae or Oscillatoria tenuis. Calculated CHCl₃ levels which might have formed at pH 7 in the water supplies were well below the maximum contaminant level (MCL) of 0.1 mg/L proposed by the U.S. Environmental Protection Agency (USEPA) for total trihalogenated methanes. Calculated levels of CHCl₃ which might have been formed under more alkaline conditions, however, were more than 10% of the MCL and were therefore significant. Calculated levels of combined forms of chlorine yielding falsely positive tests for free chlorine in some samples were slightly less or exceeded the 0.5 mg/L free chlorine residual generally taken as an acceptable level of disinfection. The demonstration of a parallel increase in organic nitrogen content with population density in two laboratory grown blue-green algal cultures, and the finding of elevated organic nitrogen values in a water supply sample collected during the occurrence of a blue-green algal bloom, suggested that summer algal bloom occurrence can add considerably to the organic nitrogen content and the trihalomethane potential of water supplies.     

Measurement of organic compound emission using small test chambers

Organic compounds emitted from a variety of indoor materials have been measured using small (166 L) environmental test chambers. The paper discusses: a) factors to be considered in small chamber testing; b) parameters to be controlled; c) the types of results obtained. The following types of materials have been tested: adhesives, caulks, pressed wood products, floor waxes, paints, and solid insecticides. Selected data are presented. For each material, chamber concentrations of organic compounds have been determined for a range of environmental conditions (e.g., air exchange rate, temperature and relative humidity). Emission rates for individual organic compounds, as well as total measured organics, were calculated. The effects of environmental variables on emission rates have been evaluated. Models are used to evaluate the effect of chamber walls and concentration on emission rates.     

The mortality effect of ship-related fine particulate matter in the Sydney greater metropolitan region of NSW,Australia

This study investigates the mortality effect of primary and secondary PM_2.5 related to ship exhaust in the Sydney greater metropolitan region of Australia. A detailed inventory of ship exhaust emissions was used to model a) the 2010/11 concentration of ship-related PM_2.5 across the region, and b) the reduction in PM_2.5 concentration that would occur if ships used distillate fuel with a 0.1% sulfur content at berth or within 300 km of Sydney. The annual loss of life attributable to 2010/11 levels of ship-related PM_2.5 and the improvement in survival associated with use of low-sulfur fuel were estimated from the modelled concentrations.In 2010/11, approximately 1.9% of the region-wide annual average population weighted-mean concentration of all natural and human-made PM_2.5 was attributable to ship exhaust, and up to 9.4% at suburbs close to ports. An estimated 220 years of life were lost by people who died in 2010/11 as a result of ship exhaust-related exposure (95% CI_β: 140–290, where CI_β is the uncertainty in the concentration-response coefficient only). Use of 0.1% sulfur fuel at berth would reduce the population weighted-mean concentration of PM_2.5 related to ship exhaust by 25% and result in a gain of 390 life-years over a twenty year period (95% CI_β: 260–520). Use of 0.1% sulfur fuel within 300 km of Sydney would reduce the concentration by 56% and result in a gain of 920 life-years over twenty years (95% CI_β: 600–1200).Ship exhaust is an important source of human exposure to PM_2.5 in the Sydney greater metropolitan region. This assessment supports intervention to reduce ship emissions in the GMR. Local strategies to limit the sulfur content of fuel would reduce exposure and will become increasingly beneficial as the shipping industry expands. A requirement for use of 0.1% sulfur fuel by ships within 300 km of Sydney would provide more than twice the mortality benefit of a requirement for ships to use 0.1% sulfur fuel at berth.