Monitoring of workers exposed to a mixture of toluene,styrene and methanol vapours by means of diffusive air sampling,blood analysis and urinalysis

Summary Exposure of 34 male workers to combined toluene, styrene and methanol was monitored by personal diffusive sampling of solvent vapours in breathing zone air, analysis of shift-end blood for the 3 solvents and analysis of shift-end urine for hippuric, mandelic and phenylglyoxylic acids and methanol. The exposure of most of the workers was below current occupational exposure limits. Regression analysis showed that a linear correlation exists for each of the 3 solvents between any pairs of the concentrations in air, blood and urine. Namely, toluene, styrene and methanol concentrations in blood obtained at the end of a shift are linearly related to the time-weighted average intensity of exposure to corresponding solvents, and also hippuric, mandelic and phenylglyoxylic acids as well as methanol in shift-end urine. The concentrations of hippuric, mandelic and phenylglyoxylic acids as well as methanol in urine correlated with the respiratory exposure intensity. Comparison of the present results with the exposure — excretion relationship after occupational exposure to the individual solvent showed that no modification in metabolism is induced by the combined exposure when exposure is low, as in the present case.     

A comparison of indoor air pollutants in Japan and Sweden: formaldehyde, nitrogen dioxide, and chlorinated volatile organic compounds

Indoor and outdoor concentrations of formaldehyde (HCHO), nitrogen dioxide (NO2), and selected chlorinated volatile organic compounds (chlorinated VOC) were measured in 37 urban dwellings in Nagoya, Japan, and 27 urban dwellings in Uppsala, Sweden, using the same sampling procedures and analytical methods. Indoor as well as outdoor air concentrations of HCHO, NO2, and chlorinated VOC were significantly higher in Nagoya than in Uppsala (P<0.01), with the exception of tetrachlorocarbon in outdoor air. In Nagoya, HCHO and NO2 concentrations were significantly higher in modern concrete houses than in wooden houses and higher in newer (less than 10 years) than in older dwellings (P<0.01), possibly due to less natural ventilation and more emission sources in modern buildings. Dwellings heated with unvented combustion sources had significantly higher indoor concentrations of NO2 than those with clean heating (P<0.05). Moreover, dwellings with moth repellents containing p-dichlorobenzene had significantly higher indoor concentrations of p-dichlorobenzene (P<0.01). In conclusion, there appear to be differences between Nagoya and Uppsala with respect to both indoor and outdoor pollution levels of the measured pollutants. More indoor pollution sources could be identified in Nagoya than in Uppsala, including construction and interior materials emitting VOC, use of unvented combustion space heaters, and moth repellents containing p-dichlorobenzene.     

Spatial analysis of exposure to traffic-related air pollution at birth and childhood atopic asthma in Toronto,Ontario

Findings from the Toronto Child Health Evaluation Questionnaire (TCHEQ) study indicate that early childhood exposure to traffic-related air pollution (TRAP) is related to the onset of atopic childhood asthma. To test this hypothesis further, we investigated whether spatial patterns in the birth neighbourhood of TCHEQ subjects with atopic asthma (136 of 909 schoolchildren in grades 1–2) could be explained by TRAP and other risk factors. If a causal relationship exists between early childhood residential exposure to TRAP and the development of atopic asthma, we hypothesise that (1) clusters of current asthma should exist around the place of residence at birth, and (2) accounting for residential concentrations of TRAP at birth should explain some of the autocorrelation. Several high asthma clusters were observed. Adjusting for TRAP completely explained one cluster; elsewhere, clusters were only partially explained by TRAP. Findings suggest that exposure during early childhood to TRAP in Toronto is an important contributor to the development of the atopic asthma phenotype and reveal the likely importance of other risk factors not measured in the fixed effects of the model.     

Absorption of polycyclic aromatic hydrocarbons by Pinus bark: analytical method and use for environmental pollution monitoring in the Palermo area (Sicily, Italy)

In the light of using biomaterial as pollutants sorbents for the environmental biomonitoring, we report here the results of the absorption of polycyclic aromatic hydrocarbons (PAHs) by pine bark. Quantitative analysis of 19 different polycyclic aromatic compounds was performed, after Soxhlet extraction in dichloromethane, by means GC–MS technique. Pinus was chosen due to its wide distribution in the Mediterranean area. The passive absorption of PAH by pine bark in the metropolitan areas allowed us to evaluate the air quality of Palermo. The obtained results showed a very high range of PAHs concentrations, from 33 μg/kg (bark dry weight), as ΣPAHs, at the control site to 1015 μg/kg along a road with high traffic flow.     

Impact of urban air pollutants and noise levels over daily hospital admissions in children in Madrid: a time series analysis

Objective: The aim of this paper was to analyse the effects of the urban air pollutants and noise levels on daily emergency hospital admissions of children less than 10 years of age in Madrid. Material and methods: Poisson Regression Models were used to quantify the associations. Meteorological variables, influenza epidemics, pollen concentrations and trends and periodicities were used as controlling variables. Results: The main results obtained were the detected relationship (p<0.05) between emergency hospital admissions due to organic diseases and noise levels (AR=2.4%) and for PM₁₀ concentrations (AR=2.1%). For respiratory diseases statistically significant associations were detected for noise levels (AR=4.7%) and cold temperatures (AR=3.8%). The main association detected for causes of admissions due to bronchitis was for O₃ (AR=36.8%) and for pneumonia was for noise levels (AR=7.7%). Conclusion: The results obtained suggest that noise level particularly is a risk factor for daily emergency hospital admissions for organic and respiratory diseases in children less than 10 years old in Madrid.     

Determination of nitrogen dioxide, sulfur dioxide, ozone, and ammonia in ambient air using the passive sampling method associated with ion chromatographic and potentiometric analyses

Concentrations of nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃), and ammonia (NH₃) were determined in the ambient air of Al-Ain city over a year using the passive sampling method associated with ion chromatographic and potentiometric detections. IVL samplers were used for collecting nitrogen and sulfur dioxides whereas Ogawa samplers were used for collecting ozone and ammonia. Five sites representing the industrial, traffic, commercial, residential, and background regions of the city were monitored in the course of this investigation. Year average concentrations of ≤59.26, 15.15, 17.03, and 11.88 μg/m³ were obtained for NO₂, SO₂, O₃, and NH₃, respectively. These values are lower than the maxima recommended for ambient air quality standards by the local environmental agency and the world health organization. Results obtained were correlated with the three meteorological parameters: humidity, wind speed, and temperature recorded during the same period of time using the paired t test, probability p values, and correlation coefficients. Humidity and wind speed showed insignificant effects on NO₂, SO₂, O₃, and NH₃ concentrations at 95% confidence level. Temperature showed insignificant effects on the concentrations of NO₂ and NH₃ while significant effects on SO₂ and O₃ were observed. Nonlinear correlations (R ² ≤ 0.722) were obtained for the changes in measured concentrations with changes in the three meteorological parameters. Passive samplers were shown to be not only precise (RSD ≤ 13.57) but also of low cost, low technical demand, and expediency in monitoring different locations.     

A time-series analysis of any short-term effects of meteorological and air pollution factors on preterm births in London, UK

Although much is known about the incidence and burden of preterm birth, its biological mechanisms are not well understood. While several studies have suggested that high levels of air pollution or exposure to particular climatic factors may be associated with an increased risk of preterm birth, other studies do not support such an association. To determine whether exposure to various environmental factors place a large London-based population at higher risk for preterm birth, we analyzed 482,568 births that occurred between 1988 and 2000 from the St. Mary's Maternity Information System database. Using an ecological study design, any short-term associations between preterm birth and various environmental factors were investigated using time-series regression techniques. Environmental exposures included air pollution (ambient ozone and PM(10)) and climatic factors (temperature, rainfall, sunshine, relative humidity, barometric pressure, and largest drop in barometric pressure). In addition to exposure on the day of birth, cumulative exposure up to 1 week before birth was investigated. The risk of preterm birth did not increase with exposure to the levels of ambient air pollution or meteorological factors experienced by this population. Cumulative exposure from 0 to 6 days before birth also did not show any significant effect on the risk of preterm birth. This large study, covering 13 years, suggests that there is no association between preterm births and recent exposure to ambient air pollution or recent changes in the weather.     

Changes in the lead isotopic composition of blood, diet and air in Australia over a decade: globalization and implications for future isotopic studies

Source apportionment in biological or environmental samples using the lead isotope method, where there are diverse sources of lead, relies on a significant difference between the isotopic composition in the target media and the sources. Because of the unique isotopic composition of Australian lead, source apportionment has been relatively successful in the past. Over the period of a decade, the 206Pb/204Pb ratio for Australian (mainly female) adults has shown an increase from a geometric mean of 16.8-17.3. Associated with this increase, there has been a decrease in mean blood lead concentration from 4.7 to 2.3 microg/dL, or about 5% per year, similar to that observed in other countries. Lead in air, which up until 2000 was derived largely from the continued use of leaded gasoline, showed an overall increase in the 206Pb/204Pb ratio during 1993-2000 from 16.5 to 17.2. Since 1998 the levels of lead in air were less than 0.2 microg/m3 and would contribute negligibly to blood lead. Over the 10-year period, the 206Pb/204Pb ratio in diet, based mainly on quarterly 6-day duplicate diets, increased from 16.9 to 18.3. The lead concentration in diet showed a small decrease from 8.7 to 6.4 microg Pb/kg although the daily intake increased markedly from 7.4 to 13.9 microg Pb/day during the latter part of the decade probably reflecting differences in demographics. The changes in blood lead from sources such as lead in bone or soil or dust is not dominant because of the low 206Pb/204Pb ratios in these media. Unless there are other sources not identified and analysed for these adults, it would appear that in spite of our earlier conclusions to the contrary, diet does make an overall contribution to blood lead, and this is certainly the case for specific individuals. Certain population groups from south Asia, south-east Asia, the Middle East and Europe (e.g. UK) are unsuitable for some studies as their isotopic ratios in blood are converging towards the increasing Australian values. The increases in blood 206Pb/204Pb ratio combined with globalization, which has resulted in the increases in 206Pb/204Pb ratio for diet, means that isotopic studies undertaken with a high degree of certainty of outcomes over a decade ago, are now considerably more difficult, not only in Australia but also in other countries where the isotopic differences are even less than in Australia.     

The influence of location, source, and emission type in estimates of the human health benefits of reducing a ton of air pollution

The benefit per ton ($/ton) of reducing PM_2.5 varies by the location of the emission reduction, the type of source emitting the precursor, and the specific precursor controlled. This paper examines how each of these factors influences the magnitude of the $/ton estimate. We employ a reduced-form air quality model to predict changes in ambient PM_2.5 resulting from an array of emission control scenarios affecting 12 different combinations of sources emitting carbonaceous particles, NO _x , SO _x , NH₃, and volatile organic compounds. We perform this modeling for each of nine urban areas and one nationwide area. Upon modeling the air quality change, we then divide the total monetized health benefits by the PM_2.5 precursor emission reductions to generate $/ton metrics. The resulting $/ton estimates exhibit the greatest variability across certain precursors and sources such as area source SO _x , point source SO _x , and mobile source NH₃. Certain $/ton estimates, including mobile source NO _x , exhibit significant variability across urban areas. Reductions in carbonaceous particles generate the largest $/ton across all locations.