Benzene exposure in Helsinki,Finland

Personal exposures and microenvironmental concentrations of benzene were measured in the residential indoor, residential outdoor and workplace environments for 201 participants in Helsinki, Finland, as a component of the EXPOLIS-Helsinki study. Median benzene personal exposures were 2.47 (arithmetic standard deviation (ASD)=1.62) μg m⁻³ for non-smokers, 2.89 (ASD=3.26) μg m⁻³ for those exposed to environmental tobacco smoke in any microenvironment and 3.08 (ASD=10.04) μg m⁻³ for active smokers. Median residential indoor benzene concentrations were 3.14 (ASD=1.51) μg m⁻³ and 1.87 (ASD=1.93) μg m⁻³ for environments with and without tobacco smoke, respectively. Median residential outdoor benzene concentrations were 1.51 (ASD=1.11) μg m⁻³ and median workplace benzene concentrations were 3.58 (ASD=1.96) μg m⁻³ and 2.13 (ASD=1.49) μg m⁻³ for environments with and without tobacco smoke, respectively. Multiple step-wise regression identified indoor benzene concentrations as the strongest predictor for personal benzene exposures of those not exposed to tobacco smoke, followed sequentially by time spent in a car, time in the indoor environment, indoor workplace concentrations and time in the home workshop. Relationships between indoor and outdoor microenvironment concentrations and personal exposures showed considerable variation between seasons, due to differences in ventilation patterns of homes in these northern latitudes. Automobile use-related activities were significantly associated with elevated benzene levels in personal and indoor measurements when tobacco smoke was not present, which demonstrates the importance of personal measurements in the assessment of exposure to benzene.     

Effects of oxygen exposure on anaerobic digester sludge.

Recuperative thickening of anaerobic digester sludge (thickening with solids return) yields increased digester capacity. Common thickening methods cause oxygen exposure to the digester sludge. This study evaluated the effects of various levels of oxygen exposure on the acetoclastic methanogens. Gravity belt thickening had no detrimental effect on the acetoclastic activity. From a 7-day batch test with continuous oxygen exposure of digester sludge, a 12% loss in acetoclastic activity was predicted for a digester with a 20-day solids retention time (SRT) and 100% recycle with recuperative thickening via dissolved air flotation thickening. However, a greater loss (27%) was found from a long-term, bench-scale digester operated under similar conditions. This loss did not affect the digester performance, as measured by volatile solids destruction. This research suggests that recuperative thickening may not affect digester performance at a long SRT with constant operation, but may change the reserve capacity of the anaerobic community.     

Comparison of breath CO,CO exposure,and Coburn model predictions in the U.S. EPA Washington-Denver (CO) study

The U.S. EPA studied the carbon monoxide (CO) exposures and resulting breath CO concentrations of 625 non-smoking persons in Washington, D.C., and 454 non-smokers in Denver, CO, in the winter of 1982–83. Mean population-weighted breath concentrations were 5.1 ± 0.2 (SE) ppm in Washington and 7.2 ± 0.2 ppm in Denver. These values were correlated with the preceding personal air CO exposures (Spearman rank correlation coefficient r_s > 0.5, P < 0.0001) but not with the outdoor concentrations (r_s < 0.2). However, the breath measurements did not agree very closely with the personal exposures according to the current (Coburn) model relating alveolar CO to ambient CO. One reason for the discrepancy may have been the slight observed negative bias displayed by the personal monitors. A method of using the breath measurements to arrive at an improved estimate of personal exposures has been developed and applied. The method leads to an upward revision of exposure estimates: about 10% of the Washington target population of 1.22 million non-smokers are estimated to have exceeded the EPA 8-h ambient standard of 9 ppm during the winter of 1982–83, well above the 3.5% indicated by the personal monitor measurements.     

Reproductive toxicity of lead,cadmium, and phthalate exposure in men

Environmental toxicants viz lead or cadmium and phthalate esters (di(2-ethylhexyl) phthalate [DEHP], dibutyl phthalate [DBP], and diethyl phthalate [DEP]) widely found in different environmental strata are linked to deteriorating male reproductive health. The objective was to assess the relationships between the seminal lead, cadmium, and phthalate (DEHP, DBP, DEP) concentrations at environmental level and serum hormone levels and semen quality in non-occupationally exposed men and specify the effect of individual and combined exposure of toxicants on semen quality. A study of 60 male partners of couples attending the Andrology Laboratory of the Reproductive Biology Department, All India Institute of Medical Sciences (AIIMS), New Delhi, India for semen analysis to assess their inability to achieve a pregnancy was selected for the study. The results of univariate and stepwise multiple regression analysis in the unadjusted model showed a significant correlation between lead or cadmium and phthalates DEHP/DBP/DEP and sperm motility, sperm concentration, and DNA damage. After adjusting for potential confounders, an association with lead or DEHP was only observed. The present data shows that lead (Pb) or cadmium (Cd) or phthalates might independently contribute to decline in semen quality and induce DNA damage. Phthalates might influence reproductive hormone testosterone. These findings are significant in light of the fact that men are exposed to a volley of chemicals; however, due to the small sample size, our finding needs to be confirmed in a larger population.     

Modelling photochemical oxidant formation, transport, deposition and exposure of terrestrial ecosystems

The chemical processes responsible for production of photochemical oxidants within the troposphere have been the subject of laboratory and field study throughout the last three decades. During the same period, models to simulate the atmospheric chemistry, transport and deposition of ozone (O(3)) from individual urban sources and from regions have been developed. The models differ greatly in the complexity of chemical schemes, in the underlying meteorology and in spatial and temporal resolution. Input information from land use, spatial and temporally disaggregated emission inventories and meteorology have all improved considerably in recent years and are not fully implemented in current models. The development of control strategies in both North America and Europe to close the gaps between current exceedances of environmental limits, guide values, critical levels or loads and full compliance with these limits provides the focus for policy makers and the support agencies for the research. The models represent the only method of testing a range of control options in advance of implementation. This paper describes currently applied models of photochemical oxidant production and transport at global and regional scales and their ability to simulate individual episodes as well as photochemical oxidant climatology. The success of current models in quantifying the exposure of terrestrial surfaces and the population to potentially damaging O(3) concentrations (and dose) is examined. The analysis shows the degree to which the underlying processes and their application within the models limit the quality of the model products.     

Sources of personal exposure to fine particles in Toronto, Ontario, Canada

Individuals are exposed to particulate matter from both indoor and outdoor sources. The aim of this study was to compare the relative contributions of three sources of personal exposure to fine particles (PM2.5) by using chemical tracers. The study design incorporated repeated 24-hr personal exposure measurements of air pollution from 28 cardiac-compromised residents of Toronto, Ontario, Canada. Each study participant wore the Rupprecht & Patashnick ChemPass Personal Sampling System 1 day a week for a maximum of 10 weeks. During their individual exposure measurement days the subjects reported to have spent an average of 89% of their time indoors. Particle phase elemental carbon, sulfate, and calcium personal exposure data were used in a mixed-effects model as tracers for outdoor PM2.5 from traffic-related combustion, regional, and local crustal materials, respectively. These three sources were found to contribute 13% +/- 10%, 17% +/- 16%, and 7% +/- 6% of PM2.5 exposures. The remaining fraction of the personal PM2.5 is hypothesized to be predominantly related to indoor sources. For comparison, central site outdoor PM2.5 measurements for the same dates as personal measurements were used to construct a receptor model using the same three tracers. In this case, traffic-related combustion, regional, and local crustal materials were found to contribute 19% +/- 17%, 52% +/- 22%, and 10% +/- 7%, respectively. Our results indicate that the three outdoor PM2.5 sources considered are statistically significant contributors to personal exposure to PM2.5. Our results also suggest that among the Toronto subjects, who spent a considerable amount of time indoors, exposure to outdoor PM2.5 includes a greater relative contribution from combustion sources compared with outdoor PM2.5 measurements where regional sources are the dominant contributor.     

Anticoagulant rodenticide exposure in raptors from Ontario,Canada

Environmental Science and Pollution Research - Anticoagulant rodenticides (ARs) are used globally to control rodent pest infestations in both urban and agricultural settings. It is well documented...     

Infant exposure to polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls (PCDD/Fs, PCBs)--correlation between prenatal and postnatal exposure

Polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are recognized environmental endocrine disruptors, which are environmentally persistent and may bio-accumulate in human bodies. Pregnant and nursing women may pass these pollutants to their babies both trans-placentally and lactationally. We measured and examined correlations of the levels of PCDD/Fs and PCBs in perinatal venous serum, placenta, umbilical-cord serum (representing prenatal exposure), and breast milk (postnatal exposure). Subjects included pregnant women without clinical complication between the ages of 25 and 35, who delivered their babies during 2000.12.01 and 2001.11.30 in central Taiwan. A total of 20 participants were randomly selected from those provided the four biological specimens for analysis of 17 PCDD/Fs, and 12 dioxin-like PCBs and six indicator PCBs using high-resolution gas chromatography/high-resolution mass spectrometry. Higher PCDD/F levels were found in placenta (10.3 TEq-pg/g lipid) and venous serum (9.1 TEq-pg/g lipid) compared to those in breast milk (7.6 TEq-pg/g lipid). Pearson and Spearman correlation analyses showed well association of PCDD/F and PCB levels between different specimens. The total dioxin/PCB level in milk, venous and cord serum can be well predicted by that in placenta through regression functions. This first study of multi-specimen correlation further established rather consistent ratios of these chemical concentrations in various specimens relative to those in venous serum.     

Dioxin exposure and public health in Chapaevsk, Russia

One of the largest environmental polluters in Chapaevsk (Samara Region, Russia) is the Middle Volga chemical plant. From 1967 to 1987, it produced hexachlorocyclohexane (lindane) and its derivatives. Currently, it produces crop protection chemicals (liquid chlorine acids, methyl chloroform, vinyl chloride, and some other chemicals). Dioxins were detected in air (0.116 pg/m3), in soil (8.9-298 ng/kg), in the town's drinking water (28.4-74.1 pg/liter), and in the cow's milk (the content of 2,3,7,8-TCDD was 17.32 pg TEQ/g fat). The mean content of dioxins in seven pooled samples of human milk (40 individual trials) was 42.26 pg TEQ/g fat, in four female workers' blood samples -412.4 pg TEQ/g fat, in six residents blood samples (those who lived 1-3 km from the chemical plant) -75.2 pg TEQ/g fat, in four residents' blood samples (5-8 km from the plant) -24.5 pg TEQ/g fat. To assess cancer risk and reproductive health status, official medical statistical information was used. In general, the male cancer mortality observed rate in Chapaevsk is higher than expected. The SMR is higher for lung cancer 3.1(C.I. 2.6-3.8), urinary organs 2.6(C.I. 1.7-3.6). Chapaevsk women have a higher risk overall due to breast cancer 2.1(C.I. 1.6-2.7) and cervix cancer 1.8(C.I. 1.0-3.1). The incidence rates were higher for lung cancer in males and for female breast cancer in all age groups compared to Russia and Samara Region in 1998. Significant disruptions in reproductive function were detected. The mean frequency of spontaneous abortions in the last seven years was statistically higher 24.4% in Chapaevsk (compared to other of the towns region). The average rate of premature labor was 45.7 per 1000 women in Chapaevsk that is significantly higher than in most Samara Region towns. The frequency of newborns with low birth weight was 7.4%. In Russia and in most of the Samara Region towns, this rate is lower (6.2-5.1%) but not statistically different. For the determination of congenital morphogenetic conditions (CMGC), 369 children born between 1990 and 1995 were examined. The average number of CMGC per child was significantly higher, 4.5 for boys and 4.4 for girls. The first results indicated serious disruptions associated with high dioxin levels in human milk and blood in Chapaevsk. We suggest that Chapaevsk is an incredibly interesting site for further environmental-epidemiological research to assess the impact of dioxins on human health.     

Dioxin incinerator emissions exposure study Times Beach, Missouri

PURPOSE: To determine whether living in the vicinity of a hazardous waste incinerator that was burning material contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increased TCDD and toxicity equivalencies (TEQ) in individuals living near the incinerator. METHODS: Participants were randomly chosen from an area close to the incinerator and compared to participants outside of the exposure area. TCDD and related compounds were measured in blood serum before incineration, four months after incineration started, and at the end of incineration. RESULTS: Lipid adjusted serum levels of TCDD and TEQ decreased from pre-incineration to four months after incineration, and decreased further by the end of incineration. CONCLUSION: Incineration of TCDD did not result in any measurable exposure to the population surrounding the incinerator.     

Occupational effect of phosfolan insecticide on spraymen during field exposure.

Phosfolan (Cyolane), 2-(diethoxy phosphinylimino)-1,3-dithiolane is one of the widely used insecticides in Egypt specially to protect cotton plants. The hazard of exposure of the spray workers team in the field was estimated in terms of the amount of Phosfolan insecticide retained on workmen body pads during field spraying. The health effect of such exposure was determined through recording of the AChE inhibition in the red blood cells at different intervals after exposure. The calculated percentage of the toxic dose received per every spraying day for each worker varied with the type of job in the range of 0.008 to 0.03 percent. The body of the mixer received the maximum exposure with 10 to 12 fold that of the assistants. The highly exposed group of workers suffered from 31 to 44 percent RBC's AChE inhibition. About half of the inhibited enzyme activity recovered after 48 hours. Then it took more than 3-4 weeks to reach complete recovery. Thus the RBC's AChE activity can be recommended as a criterion for the level of exposure to organophosphorous insecticides.     

Occupational exposure to synthetic musks in barbershops,compared with the common exposure in the dormitories and households

Synthetic musks (SMs) have been widely used as fragrance ingredients in personal care and sanitary commodities. Due to their high volatility and particle-binding affinity, the indoor dust is a major reservoir of SMs, and dust ingestion could be an important exposure way to special populations, such as hairdressers. In spite of the known toxicity of SMs, there is no information regarding the occurrence of SMs in barbershop dusts and the exposure of hairdressers through indoor dust ingestion. In the present study, the levels of two nitro musks and five polycyclic musks were measured from indoor dust samples collected from barbershops, and some other indoor dust samples were also collected from dormitories, bathhouses and households for comparison. The concentrations of ∑SMs in barbershop dusts were 10–100 times higher than those from the other three indoor microenvironments. Polycyclic musks accounted for 89.4% of ∑SMs on average in all samples, of which two compounds, HHCB and AHTN jointly dominated 97.9% of polycyclic musks. The levels of HHCB and AHTN varied from 12.2 to 8.39 × 10⁵ and from 13.2 to 3.49 × 10⁵ ng g⁻¹, respectively. The daily intakes (DIs) of ∑SMs through house dust ingestion were estimated using the model of high dust ingestion and worst-case exposure (P95), and the corresponding exposure rates were 2791, 135 and 727 ng d⁻¹ for the hairdressers, general population and toddlers. SMs were also detected in blood samples collected from the hairdressers and normal adults (n = 50 and 10, respectively). There was no significant difference between these two groups. Despite the absence of higher SM concentrations in hairdresser’s blood, we should not overlook the potential occupational health risks due to their high SMs ingestion rate.     

Assessment of soil lead exposure in children in Shenyang, China

Soil lead pollution is serious in Shenyang, China. The paper brings together the soil work, the bioaccessibility, and the blood lead data to assess the soil lead exposure in children in Shenyang, China. Approximately 15.25% of the samples were above China Environment Protection Agency guideline concentration for soil Pb to protect human from health risk (350 mgkg(-1)). Pb concentrations varied among use scenarios. The main lead contamination sources are industry emission and automobile exhaust. Bioaccessibility also varied among use scenarios. Children, who ingested soil from industrial area, public parks, kindergarten playground, and commercial area, are more susceptible to soil lead toxicity. The industrial area soil samples presented higher bioaccessibility compared to the other use scenario soil samples contaminated by automobile exhaust. The result also suggested a most significant linear relationship between the level of Pb contamination and the amount of Pb mobilized from soil into ingestion juice. Soil pH seemed to have insignificant influence on bioaccessibility in the present study. Bioaccessibility was mainly controlled by other factors that are not investigated in this study. A linear relationship between children blood lead and soil intestinal bioaccessibility was present in the study. Children who are 4-5 years old are more likely to demonstrate the significant relationship between soil lead bioaccessibility and blood lead as their behaviors place them at greatest risk of soil lead toxicity, and their blood lead levels are more likely to represent recent exposure.     

Spatially distributed pesticide exposure assessment in the Central Valley, California, USA

Field runoff is an important transport mechanism by which pesticides move into the hydrologic environment of intensive agricultural regions such as California's Central Valley. This study presents a spatially explicit modeling approach to extend Pesticide Root Zone Model (PRZM), a field-scale pesticide transport model, into basin level. The approach was applied to simulate chlorpyrifos use in the Central Valley during 2003-2007. The average value of loading as percent of use (LAPU) is 0.031%. Results of this study provide strong evidence that surface runoff generation and pesticide application timing are the two influencing factors on the spatial and temporal variability of chlorpyrifos sources from agricultural fields. This is one of the first studies in coupling GIS and field-scale models and providing simulations for the dynamics of pesticides over an agriculturally dominated landscape. The demonstrated modeling approach may be useful for implementations of best management practice (BMP) and total maximum daily load (TMDL).     

PCB, PCDF, and PCDD exposure following a transformer fire: Chicago

On September 28, 1983, an electrical fire in a transformer vault resulted in the loss of 15 gallons of transformer oil composed of 65% PCBs (Aroclor 1260) and 35% trichlorobenzene and forced the precautionary evacuation of a major Chicago office building. A square foot wipe sample of soot on the vault ceiling contained 28,000 ng total TCDFs, 3,800 ng 2,3,7,8-TCDF, 40,000 ng PCDFs, 33,000 ng HxCDFs, 11,200 ng HpCDFs, 1,238 ng OCDFs, 314 ng HpCDDs, and 127 ng OCDDs. No PCDFs or PCDDs were detected in the blood (detection limit 3–40 ppt) of two fire fighters hospitalized with smoke inhalation nor of two office employees similarly exposed.     

Occupational exposure

Concentrations of polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), hexachlorobenzene and methylsulphonyl metabolites of PCB were determined in blood plasma from potentially exposed workers and controls. Three of the potentially exposed subjects had worked with cable incineration and two were electricians. Extraction of the organochlorine compounds and lipids were performed using the lipophilic gel Lipidex. Different adsorbents and gel permeation chromatography were applied for further purification of the samples and separation of analytes. Determinations of the chlorinated compounds were made by using gas chromatography with electron-capture detection and gas chromatography-mass spectrometry. Only small differences in the concentrations of organochlorine compounds were found in the plasma from the three subject groups. Thus, specific exposure of the workers could not be confirmed.     

Occupational exposure

Concentrations of polychlorinated biphenyls (PCB), polychlorinated naphthalenes (PCN), polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), hexachlorobenzene and methylsulphonyl metabolites of PCB were determined in blood plasma from potentially exposed workers and controls. Three of the potentially exposed subjects had worked with cable incineration and two were electricians. Extraction of the organochlorine compounds and lipids were performed using the lipophilic gel Lipidex. Different adsorbents and gel permeation chromatography were applied for further purification of the samples and separation of analytes. Determinations of the chlorinated compounds were made by using gas chromatography with electron-capture detection and gas chromatography-mass spectrometry. Only small differences in the concentrations of organochlorine compounds were found in the plasma from the three subject groups. Thus, specific exposure of the workers could not be confirmed.     

Ozone exposure

Increased tropospheric ozone concentrations cause damage to both human health and the environment. To assess the exposure of forest areas and selected tree species to ozone, it is necessary to calculate the ozone exposure distribution. The present article describes the application of an ozone interpolation model to the calculation of the ozone exposure distribution in combination with forest inventory data. The exposure of forest regions to ozone was assessed by means of an AOT40 map (accumulated ozone exposure over a threshold of 40 ppb). The calculation was performed by hourly running of the model during the summer term and accumulation of the patterns that exceeded 40 ppb. The exposure of the primary Austrian tree species to ozone can be assessed due to the spatial relation of ozone exposure and tree species patterns. This spatial relation also allows the verification of assumptions concerning ozone-related tree damage.