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PubMed2006

Preparation and validation of gridded emission inventory of criteria air pollutants and identification of emission hotspots for megacity Delhi.

Delhi is one of the many megacities struggling with punishing levels of pollution from industrial, residential, and transportation sources. Over the years, pollution abatement in Delhi has become an important constituent of state policies. In the past one decade a lot of policies and regulations have been implemented which have had a noticeable effect on pollution levels. In this context, air quality models provide a powerful tool to study the impact of development plans on the expected air pollution levels and thus aid the regulating and planning authorities in decision-making process. In air quality modeling, emissions in the modeling domain at regular interval are one of the most important inputs. From the annual emission data of over a decade (1990-2000), emission inventory is prepared for the megacity Delhi. Four criteria pollutants namely, CO, SO(2), PM, and NO(x) are considered and a gridded emission inventory over Delhi has been prepared taking into account land use pattern, population density, traffic density, industrial areas, etc. A top down approach is used for this purpose. Emission isopleths are drawn and annual emission patterns are discussed mainly for the years 1990, 1996 and 2000. Primary and secondary areas of emission hotspots are identified and emission variations discussed during the study period. Validation of estimated values is desired from the available data. There is a direct relationship of pollution levels and emission strength in a given area. Hence, an attempt has been made to validate the emission inventory for all criteria pollutants by analyzing emissions in various sampling zones with the ambient pollution levels. For validation purpose, the geographical region encompassing the study area (Delhi) has been divided into seven emission zones as per the air quality monitoring stations using Voronoi polygon concept. Dispersion modeling is also used for continuous elevated sources to have the contributing emissions at the ground level to facilitate validation. A good correlation between emission estimates and concentration has been found. Correlation coefficient of 0.82, 0.77, 0.58 and 0.68 for CO, SO(2), PM and NO(x) respectively shows a reasonably satisfactory performance of the present estimates.

Air Pollutants↗
PubMed1977

Metallobiochemistry of heavy metal pollution: nuclear and radiochemical techniques for long term--low level exposure (LLE) experiments.

The chronic exposure of man to increasing amounts of heavy metals as a consequence of environmental pollution, requires accurate knowledge of how much the homeostatic control of trace elements can stand increased exposure to abnormal amounts of metal pollutants without alteration of the biochemical functions. This topic includes the study of the accumulation of metal pollutants in the body with the identification of metal biocomplexes under long term-low level exposure (LLE) conditions. Extremely sensitive analytical techniques are required for experimentation at the heavy metal levels which are typical of a polluted environment in order to assess the limits of physiological homeostatic controls. The possiblity of applying nuclear and radiochemical techniques, such as neutron activation analysis, multiple tracing, high resolution gamma-ray spectrometry and Cerenkov counting, coupled with biochemical techniques, such as gel filtration, ion-exchange chromatography, polyacrylamide gel electrophoresis and differential centrifugation, has been demonstrated in various typical applications in metallobiochemistry. The subject of the first part of this paper is the development and improvement of the techniques, dealing with potential metal binding components, such as metalloenzymes and nucleic acids chosen as models. The developments refer to: preparation of labelled metal pollutants with very high specific activity to label in vivo nanogram or subnanogram amounts of pollutant metals; neutron activation analysis of enzymes and nucleic acids with the aim of analyzing concentrations of many metal pollutants in the identified metal binding components of the microsamples; radiochemical methods including radiobiochemical techniques for multielement tracer experiments and for studying the interaction of heavy metas and metal binding components; development of complementary counting techniques. The in vivo applications are centered on biochemical studies on cadmium, in particular on the long term-low exposure experiment, which is under investigation at present, with the identification of both critical organs of accumulation and of the cadmium binding components. Results are given for biochemical mechanisms involving cadmium such as the stimulation of the "de novo" biosynthesis of rat liver and intestine cadmium binding proteins (CdBP) and on the systematic study of the interaction of metal pollutants and rat liver cadmium binding proteins itself. Preliminary data are also given for short term experiments dealing with the identification of cellular metal binding components for V, Se, Cd and Pb.

Alkaline Phosphatase↗
PubMed2005

Air pollution and hospital admissions for cardiovascular disease in Taipei, Taiwan.

This study was undertaken to determine whether there is an association between air pollutants levels and hospital admissions for cardiovascular diseases (CVD) in Taipei, Taiwan. Hospital admissions for CVD and ambient air pollution data for Taipei were obtained for the period 1997-2001. The relative risk of hospital admission was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. For the one-pollutant models, on warm days (>or=20 degrees C) statistically significant positive associations were found between levels of particulate matter <10-microm aerodynamic diameter (PM10), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3). On cool days (<20 degrees C), all pollutants except O3 and SO2 were significantly associated with CVD admissions. For the two-pollutant models, CO, NO2, and O3 were significant in combination with each of the other four pollutants on warm days. On cool days, PM10 remained statistically significant in all the two-pollutant models. This study provides evidence that higher levels of ambient pollutants increase the risk of hospital admissions for CVD.

Air Pollutants↗
PubMed2005

Decreased fertility in mice exposed to environmental air pollution in the city of Sao Paulo.

It has largely been shown that air pollution can affect human health. Effects on human fertility have been shown mainly in males by a decrease in semen quality. Few studies have focused on the environmental effects on female fertility. The aim of the present study was to analyze the effects of air pollution in the city of Sao Paulo on mouse female fertility. Four groups of female Balb/c mice were placed in two chambers 10 days (newborn) or 10 weeks (adults) after birth. Mice were maintained in the chambers 24 h a day, 7 days a week, for 4 months. The first chamber received air that had passed through an air filter (clean chamber) and the second received ambient air (polluted chamber). We measured PM10 and NO2 inside both chambers. Mice belonging to the adult groups were bred to male mice after living for 3 months inside the chambers. The newborn groups mated after reaching reproductive age (12 weeks). After 19 days of pregnancy the numbers of live-born pups, reabsorptions, fetal deaths, corpora lutea, and implantation failures were determined. PM10 and NO2 concentrations in the clean chamber were 50% and 77.5% lower than in the polluted chamber, respectively. Differences in fertility parameters between groups were observed only in animals exposed to air pollution at an early age (10 days after birth). We observed a higher number of live-born pups per animal in the clean chamber than per animal from the polluted chamber (median=6.0 and 4.0, respectively; P=0.037). There was a higher incidence of implantation failures in the polluted group than in the clean group (median=3.5 and 2.0, respectively; P=0.048). There were no significant differences in the other reproductive parameters between groups. These results support the concept that female reproductive health represents a target of air pollutants.

Air↗
PubMed2005

River pollution from non-point sources: a new simplified method of assessment.

Assessment of the pollution of water bodies from non-point sources is a complex data- and time-consuming task. The potential non-point pollution index (PNPI), is a new tool designed to assess the global pressure exerted on rivers and other surface water bodies by different land uses. The main feature of PNPI is the wide availability of its input data. Very detailed input maps, often lacking over many areas, are not needed for PNPI calculation. As a consequence of the input data used, the modelling of physical reality and of processes is heavily simplified. The authors counterbalanced such a simplification using an 'expert system' approach. The system bypasses the accurate representation of the physical reality to assess globally the pollution potential of different land uses according to the judgement of scientists. The scientific community proposes many models for depicting the dynamics of pollutants coming from diffuse sources. Most of them can be grouped into two broad categories: statistical models and physically based models. PNPI belongs to neither of the above-mentioned groups. PNPI is a GIS-based, watershed-scale tool designed to inform decision makers and public opinion about the potential environmental impacts of different land management scenarios. PNPI applies the multicriteria technique to pollutant dynamics and water quality. The pressure exerted on water bodies by diffuse pollution coming from land units is expressed as a function of three indicators: land use, run-off and distance from the river network. They are calculated from land use data, geological maps and a digital elevation model (DEM). The weights given to different land uses and to the three indicators were set according to experts' evaluations and allow calculation of the value of the PNPI for each node of a grid representing the watershed; the higher the PNPI of the cell, the greater the potential impact on the river network. The output of the calculation is presented in the form of maps that highlight areas that are more likely to produce pollution. Last, possibilities, strategies and results of the validation of the PNPI are described. In the authors' view, the explicit link between land use and potential pollution on which PNPI is based, together with its high communication potential, make it particularly interesting for a participatory and integrated approach to land management and environmental protection.

Conservation of Natural Resources↗
PubMed2004

Air pollution, health, and socio-economic status: the effect of outdoor air quality on childhood asthma.

This paper estimates the effect of air pollution on child hospitalizations for asthma using naturally occurring seasonal variations in pollution within zip codes. Of the pollutants considered, carbon monoxide (CO) has a significant effect on asthma for children ages 1-18: if 1998 pollution levels were at their 1992 levels, there would be a 5-14% increase in asthma admissions. Also, households respond to information about pollution with avoidance behavior, suggesting it is important to account for these endogenous responses when measuring the effect of pollution on health. Finally, the effect of pollution is greater for children of lower socio-economic status (SES), indicating that pollution is one potential mechanism by which SES affects health.

Adolescent↗
PubMed2002

The validity of the Gammarus:Asellus ratio as an index of organic pollution: abiotic and biotic influences.

In freshwaters. Gammarus spp. are more sensitive to organic pollution than Asellus spp. and the relative abundance of the two taxa has been proposed as a pollution index. We tested the validity of this by examining the relationship between the Gammarus: Asellus (G : A) ratio and (1) a suite of physico-chemical variables. (2) established biotic (average score per taxon, ASPT) and richness (species richness (S) and Ephemeroptera, Plecoptera and Trichoptera families richness (EPT family richness)) indices generated from the macroinvertebrate community. In addition, we investigated a suspected biotic interaction, predation, between Gammarus and Asellus. Both univariate and multivariate analyses showed that the G: A ratio was sometimes responsive to changes in parameters linked to organic pollution, such as BOD5 and nitrate levels. However, the G : A ratio also appeared responsive to variables not directly linked to organic pollution, such as conductivity and distance from source. There were significant positive correlations among the G : A ratio and the ASPT, S and EPT, indicating that changes in the relative abundances of Gammarus and Asellus were reflected in changes in the pollution sensitivity and richness of the wider macroinvertebrate community. A laboratory experiment revealed significant predation of Asellus aquaticus juveniles by Gammarus duebeni celticus adults, but no reciprocal predation. We propose that the G: A ratio may be useful as a crude measure of organic pollution that could supplement more complex indices in a multimetric approach to pollution monitoring or be used for monitoring individual sites, where a simple technique is required for monitoring purposes over a period of time. Also, we urge recognition of the possible role of biotic interactions among taxa used in the generation of pollution indices.

Animals↗
PubMed2004

Tree rings as Pb pollution archives? A comparison of 206Pb/207Pb isotope ratios in pine and other environmental media.

Tree rings, if validated as an environmental archive for pollution, would provide a convenient, geographically widespread archive for studying the temporal and spatial distribution of atmospheric pollutants. We collected tree-ring records from Scots pine (Pinus sylvestris L.), ranging in age from 100 to 300 years and from one spruce (Picea abies), from sites in southern and northern Sweden and analyzed their stable lead isotopic composition (206Pb/207Pb). These results are compared to the Pb isotopic composition in soil profiles from each of the sites and temporal changes in the 206Pb/207Pb ratio in peat and lake sediment deposits in Sweden. The mineral soils at each site are characterized by high 206Pb/207Pb ratios (> 1.35), while the ratios in the mor layer are low (1.14-1.16) and characterized by atmospheric lead pollution. The 206Pb/207Pb ratios of the tree rings, typically approximately 1.18-1.20, indicate a significant (10-30%) contribution of Pb derived from the underlying mineral soil. While peat and lake sediment records show that the 206Pb/207Pb ratio of atmospheric deposition has varied over time, with a pronounced trough between approximately 1930 and 1990, the tree rings show no similar trend. Further comparison of published Pb isotope data from other tree-ring records with time series from peat bogs and herbarium samples also shows poor agreement, and indicates that tree rings always contain a mixture of pollution Pb and Pb from the underlying mineral soil. The majority of Pb in the wood is derived from atmospheric pollution either directly, through aerial interception, or indirectly, through uptake from the large pool of accumulated pollution Pb in the soil. Since the Pb isotope ratios of the wood indicate that some natural Pb is taken up into the tree, then it must also be concluded that some fraction of the pollution Pb in the wood is likewise taken up from the forest soil. Based on the Pb isotope analyses, we can only conclude that dendrochemical records are not useful in temporal studies of metal pollution.

Atmosphere↗
PubMed2001

Outdoor air pollutants derived from industrial processes may be causally related to the development of asthma in children.

BACKGROUND: There is no consistent evidence that outdoor air pollutants are involved in the development of asthma. OBJECTIVE: The aim of this study was to determine whether outdoor air pollutants derived from industrial processes were related to the prevalence of asthma, bronchial hyperresponsiveness, and atopy in exposed children. METHODS: A total of 7,511 children from 7 to 12 years of age were recruited in the study. Eight hundred eighty-eight of 1,009 (88%) of the subjects living around industrial factories and 5,998 of 6,502 (92%) living in a less polluted neighboring area responded to the ISAAC questionnaire. A total of 1,492 subjects 8 to 9 years old underwent skin prick tests for 11 common aeroallergens. A total of 732 of the subjects from 8 to 9 years of age underwent bronchial provocation tests with hypertonic saline (BPT-HS). RESULTS: The prevalence of ever experiencing wheezing and wheeze during the last 12 months was 25.6%, and 18.8% among the children living in the more polluted area. This was significantly higher than for those living in the less polluted area (14.2% and 9.0%, respectively). The positive rate of BPT-HS (the provocative dose of hypertonic saline causing 20% fall of FEV, < or = 23 mL) was higher among those in the more polluted area than in children living in the less polluted area (12.2% vs 7.5%). However, the rate of atopy based on the skin tests was the same in the two groups (28.3% vs 30.6%). CONCLUSIONS: The prevalence of asthma and bronchial hyperresponsiveness was higher among children living around the heavily industrial area compared with those living in the less polluted area, despite similar atopic sensitization.

Air Pollutants↗
PubMed2002

In vitro effect of air pollutants on human bronchi.

A useful approach for constructing dose-response relationships and for studying the underlying mechanisms by which a xenobiotic agent enhances airway reactivity is to measure the response of an isolated airway following ex vivo exposure to a pollutant. We have in this way determined the dose-response relationship between ex vivo exposure to pollutants such as nitrogen dioxide (NO2), the aldehyde acrolein, and ozone (O3) and the reactivity to agonists in human isolated bronchial smooth muscle. We have also investigated the underlying alteration in the cellular mechanisms of airway smooth-muscle contraction induced by such exposure and found that it is related to alteration in calcium signaling at the site of the airway smooth-muscle cell. Finally, although there is epidemiological evidence that an increase in allergic diseases such as asthma may be linked to air pollution, there are few experimental data to address this issue. The final aim of this study was therefore to investigate the interaction between passive sensitization and exposure to pollutants in human isolated airways. We have examined (i) the effect of a pre-exposure to pollutants on the contraction of sensitized bronchi in response to a specific antigen and (ii) the effect of passive sensitization on the contraction in response to nonspecific agonists in bronchi pre-exposed to pollutants. The results indicate a combined effect of immunological sensitization and exposure to pollutants; that is, passive sensitization and exposure to pollutants act in a synergistic manner on human bronchial smooth-muscle reactivity in response to both specific antigens and nonspecific agonists.

Acrolein↗
PubMed1999

Air pollution exposure monitoring and estimating. Part I. Integrated air quality monitoring system.

This paper presents an integrated exposure monitoring system, based on an expansion of existing air quality monitoring systems using dispersion modelling. The system allows: (1) identifying geographical areas whose inhabitants are most exposed to ambient pollution; (2) identifying how many people in an area are exposed to concentrations of pollution exceeding air quality guidelines; (3) describing the exposure of population subgroups (e.g. children); (4) planning pollution abatement measures and quantifying their effects; (5) establishing risk assessment and management programs, and (6) investigating the short- and long-term effects of both pollutants and pollution sources on public health. The effect of pollution is rarely very large and in order to discover it, exposure estimation must provide data that reflects both spatial and temporal variations. Estimates of pollution exposure are obtained using an integrated approach that combines results of measurements from monitoring programs with dispersion calculations. These values can serve as estimates for individual short-term or long-term exposure. The grouped data allows the expression of ambient pollution concentrations as the spatial distribution of estimates such as the mean or 98th percentile of such compounds as SO2, O3, NO2, PM10 and PM2.5. This integrated approach has been combined into a single software package, AirQUIS.

Air Movements↗
PubMed2003

The effects of air pollution on acute respiratory conditions.

OBJECTIVE: Air pollution and its potential health effects are very important worldwide. It is particularly problematic in densely populated cities of developing countries that suffer from a lack of both short- and long-term programmes for air pollution control. We decided to study the short-term effects of air pollution on lung health by assessing the relationship between the levels of six air pollutants and emergency visits for asthma and COPD exacerbations in Tehran, Iran. METHODOLOGY: We monitored the daily attendances for acute respiratory conditions (asthma attacks and COPD exacerbations) to the emergency departments of five major hospitals together with the daily concentrations of six major pollutants during a 5-month period in Tehran. The association between these acute respiratory conditions and the levels of air pollutants was determined by multiple stepwise regression. RESULTS: A correlation was observed between the number of hospital admissions for asthma and the weekly mean concentration of nitrogen dioxide (P < 0.05). The 3-day and 10-day mean concentrations of sulphur dioxide were also found to be directly associated with the number of asthma admissions during this period (P < 0.05). No direct correlation was observed for other variables. CONCLUSION: This study further emphasizes the deleterious effects of air pollution on respiratory health in major populated cities such as Tehran and suggests that increased attention needs to be given to urgent control of air pollution problems.

Adult↗
PubMedDate not supplied

Acute respiratory illness in families exposed to nitrogen dioxide ambient air pollution in Chattanooga, Tennessee.

The incidence of acute respiratory illness in families in Chattanooga, Tennessee was studied in 1972 and 1973 to determine if residents of a formerly high nitrogen dioxide exposure community continued to experience a high incidence of illness after ambient air concentrations of the pollutant had been reduced substantially. Illness data were collected by telephone at 2-wk intervals and illness rates per 100 person weeks of observation were contrasted with air pollution concentrations measured no more than 3.2 km from the home. Data were contrasted by communities designated as high, intermediate, or low pollution exposure. In 1972, higher rates of respiratory illness continued to occur in the designated high pollution area. These were associated with current higher short-term concentrations of nitrogen dioxide even though the long-term mean concentrations of the pollutant were little higher than those in the low pollution area. It was not possible to attribute the excesses in illness to specific pollutants or to specific exposure periods. However, reduction of the illness rate in 1973 associated with a strike at the primary source industry that curtailed nitrogen dioxide pollution in the high exposure community suggested that the short-term exposure may be more important than long-term exposure.

Adolescent↗
PubMedDate not supplied

Health effects of air pollution due to coal combustion in the Chestnut Ridge Region of Pennsylvania: results of cross-sectional analysis in adults.

Respiratory questionnaires (ATS-DLD-78) were administered to 5557 adult women in a rural area of Western Pennsylvania to evaluate the health effects of air pollution resulting from coal combustion. Air pollution data were derived from 17 air quality monitor sites and stratified to define low, medium, and high pollution areas. The means of 4 yr (1975-1978) annual averages for sulfur dioxide in each strata were 62, 66, and 99 micrograms/m3, respectively. Total suspended particulates were not tested as a risk factor because they reflected air pollution from sources other than coal combustion (e.g., agricultural, road dusts). Risks of respiratory symptoms were evaluated in a multiple logistic model that adjusted for several potential confounding factors. The risk of "wheeze most days or nights" in nonsmokers residing in the high and medium pollution areas was 1.58 and 1.26 (P = .02), respectively, relative to residents in the low pollution area. In the subset of residents who had lived in the same location for at least 5 yr, relative risks increased to 1.95 and 1.40 (P less than .01), respectively. An increased risk of grade 3 dyspnea in nonsmokers was associated with sulfur dioxide but did not achieve statistical significance (P = .11), and there was no association of cough or phlegm and air pollution in nonsmokers. Cigarette smoking characteristics were the major determinant of respiratory symptoms in smokers, and no independent association of air pollution was found. This study suggests that wheezing may be associated with ambient exposure to sulfur dioxide in nonsmokers, but no effect of sulfur dioxide on cigarette smokers was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Brain inflammation and Alzheimer's-like pathology in individuals exposed to severe air pollution.

Air pollution is a complex mixture of gases (e.g., ozone), particulate matter, and organic compounds present in outdoor and indoor air. Dogs exposed to severe air pollution exhibit chronic inflammation and acceleration of Alzheimer's-like pathology, suggesting that the brain is adversely affected by pollutants. We investigated whether residency in cities with high levels of air pollution is associated with human brain inflammation. Expression of cyclooxygenase-2 (COX2), an inflammatory mediator, and accumulation of the 42-amino acid form of beta-amyloid (Abeta42), a cause of neuronal dysfunction, were measured in autopsy brain tissues of cognitively and neurologically intact lifelong residents of cities having low (n:9) or high (n:10) levels of air pollution. Genomic DNA apurinic/apyrimidinic sites, nuclear factor-kappaB activation and apolipoprotein E genotype were also evaluated. Residents of cities with severe air pollution had significantly higher COX2 expression in frontal cortex and hippocampus and greater neuronal and astrocytic accumulation of Abeta42 compared to residents in low air pollution cities. Increased COX2 expression and Abeta42 accumulation were also observed in the olfactory bulb. These findings suggest that exposure to severe air pollution is associated with brain inflammation and Abeta42 accumulation, two causes of neuronal dysfunction that precede the appearance of neuritic plaques and neurofibrillary tangles, hallmarks of Alzheimer's disease.

Adult↗
PubMed2002

[A new in vitro test to simulate gastric absorption of copper, lead, tin and zinc from polluted soils].

Metals in polluted soils can be ingested by young children and cause toxicity through gastro-intestinal absorption. Very few tests are used to evaluate the gastric absorption of metals from polluted soils. The Toxicity Characteristics Leaching Procedure (TCLP) of the Environmental Protection Agency of the United States is indirectly used as usually no action is taken on a polluted soil if lead is less than 5 mg l(-1) in the test. This paper presents a new In vitro simple screening test to detect soils polluted by metals which can cause gastric absorption. The gastric juice simulation test (GJST) is based on the chemistry of the stomach. The TCLP and the GJST has been applied to six different size fractions of 5 soils. Lead carbonate was the main form of lead pollution. Lead oxide, lead silicate, lead phosphate and PbaSnbOc(CO3)d, PbaTibOc(CO3)d and PbaCrbOc were also present. Copper is mainly found as elemental copper partly carbonated while zinc is as zinc oxide or carbonate. Tin is usually associated with iron alloy or oxide or in PbaSnbOc(CO3)d. The percentage of the surface occupied by a polluting phase is higher in small particles. The proportion of particles for which pollution is located near the surface of the particle is more important for small particles. The GJST leaches more copper, lead and zinc than the TCLP, particularly on small size fractions. Inorganic tin is not solubilised by the TCLP or the GJST. The percentage of metal leached from small particles is very important with the GJST, but not with the TCLP. The pH 5 of the TCLP is too high to solubilise much metals and is not a good test to evaluate polluted soils if gastric absorption is to be considered. For two soils out of five, the TCLP didn't detect problematic soils as detected with the Integrated Exposure Uptake Biokinetic model of the USEPA. The GJST detected all the problematic soils and is better to evaluate the chemical solubility of metals in the gastric environment. The GJST better represents the stomach environment (Cl-, pH 2, T = 37 degrees C). The GJST appears to be a good test to detect metal contaminated soils.

Absorption↗
PubMed2002

Numerical evaluation of the effect of traffic pollution on indoor air quality of a naturally ventilated building.

A computational fluid dynamics technique was used to evaluate the effect of traffic pollution on indoor air quality of a naturally ventilated building for various ventilation control strategies. The transport of street-level nonreactive pollutants emitted from motor vehicles through the indoor environment was simulated using the large eddy simulation (LES) of the turbulent flows and the pollutant transport equations. The numerical model developed herein was verified by available wind-tunnel measurements. Good agreement with the measured velocity and concentration data was found. Twelve sets of numerical scenario simulations for various roof- and side-vent openness and outdoor wind speeds were carried out. The effects of the air change rate, the indoor airflow pattern, and the external pollutant dispersion on indoor air quality were investigated. The control strategies of ventilation rates and paths for reducing incoming vehicle pollutants and maintaining a desirable air change rate are proposed to reduce the impact of outdoor traffic pollution during traffic rush hours. It was concluded that the windward side vent is a significant factor contributing to air change rate and indoor air quality. Air intakes on the leeward side of the building can effectively reduce the peak and average indoor concentration of traffic pollutants, but the corresponding air change rate is relatively low. Using the leeward cross-flow ventilation with the windward roof vent can effectively lower incoming vehicle pollutants and maintain a desirable air change rate during traffic rush hours.

Air Movements↗
PubMed2000

Field trials--measuring progress in pollution prevention using a chemical hazard score.

The purpose of this investigation was to demonstrate the feasibility of a method to quantitatively measure achievement (or non-achievement) of reduced pollution generation at the source process in manufacturing, known as pollution prevention. This is societally useful since managers often need quantitative results to justify allocation of resources and United States law has designated pollution prevention as the preferred strategy for managing potential release of hazardous wastes and emissions to the environment. This paper reports the first organized field trials to test the use of the Purdue chemical hazard score to measure progress in pollution prevention. The tests were conducted of 16 processes and one cluster of three plants at the same site, considered here as a unit and called a "facility", at 11 manufacturing facilities in four manufacturing sectors, defined by US Standard Industrial Classifications. These sectors, known to use hazardous chemicals, are manufacture of motor vehicle parts, plastics resins and products, and wood products, as well as metal coating and anodizing. Among these 16 processes and an entire facility, 15 achieved pollution prevention and two did not. The degree of achievement or non-achievement of pollution prevention is quantified by this method. Measurement of progress in pollution prevention is demonstrated for safer chemical substitution, other process change, and both. This demonstration applied to manufacturing processes in which the hazardous input chemicals are not substantially changed by chemical reaction during the manufacturing process, so input masses could be used as surrogates for creation of output hazardous emissions and wastes. This project demonstrated that there was not consistency in measures of production among the facilities and processes monitored, among similar types of products, in the same manufacturing sectors. These production measures also varied in their accuracy, and reasons are given for these differences. In order to measure progress in pollution prevention effectively, and compare results across processes, facilities and sectors, standardized, accurate measures of production level need to be developed, preferably by industry.

Environmental Pollution↗