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PubMed2006

Gaseous air pollutants and hospitalization for respiratory disease in the neonatal period.

OBJECTIVE: Current levels of ambient air pollution are associated with morbidity and mortality in the general population. To determine the influence of gaseous air pollutants on neonatal respiratory morbidity, we tested the association between daily respiratory hospitalizations and daily concentrations of ambient air pollution gases: ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide, in 11 large Canadian cities. STUDY DESIGN: Daily time-series analyses were employed and results were adjusted for day of the week, temperature, barometric pressure, and relative humidity. RESULTS: The percent increases in hospitalization associated with an increase in air pollution equivalent to its interquartile range were 3.35 [95% confidence interval (CI), 1.73-4.77] for O3, 2.85 (95% CI, 1.68-4.02) for NO2, 1.66 (95% CI, 0.63-2.69) for SO2, and 1.75 (95% CI, 0.48-3.02) for CO. The independent effect of all pollutants combined was 9.61% (95% CI, 4.52-14.7%). CONCLUSION: Our results suggest that neonates are experiencing adverse effects of air pollution at current levels in Canada, and that accounts for a significant proportion of hospitalizations in this subgroup.

Air Pollutants↗

PubMed1993

Pulmonary function changes in asthmatics associated with low-level SO2 and NO2 air pollution, weather, and medicine intake. An 8-month prospective study analyzed by neural networks.

This paper presents the response in subjects with asthma to gaseous air-pollution levels, weather, and medicine intake as identified by principal-component analysis and neural network techniques. Pulmonary function measured by respiratory peak-flow rate in nonallergic asthmatics was associated with ambient, low-level, air-pollution concentrations of sulfur dioxide and nitrogen dioxide, temperature, relative humidity, and medicine intake. Results from 27 nonallergic asthmatics aged 18-60 years with well-characterized bronchial asthma and regular medical treatment were analyzed from two cities. During an 8-month period, each subject kept a diary table, which included symptoms, lung function (evening peak flow), medicine intake, and tobacco smoking. High intake of medicine and high ambient temperatures corresponded to decreased peak flow. The changes in temperature did not occur in situations with low medicine intake. During frost periods, peak-flow values decreased independently of medicine intake and levels of SO2. During other times, increased levels of SO2 and NO2 increased temperature, and increased intake of medicine, and low relative humidity corresponded to decreased peak flow. Increased levels of SO2 and NO2 corresponded synergistically to decreased peak flow at levels above 40 micrograms/m3.

Adolescent↗

PubMedDate not supplied

Evaluation of outdoor air quality in rural and urban communities.

A year-round air monitoring program for sulfur dioxide, sulfates, nitrogen dioxide, nitrates, ozone, and total suspended particulates was conducted in three towns with population densities ranging from 29/km2 to 1178/km2. The results showed significant differences in concentrations of several pollutants between the urban town and the two rural towns. However, site-to-site variation over distances of 1 mile or less within the urban area was considerable. To express pollutant loads in each town in a single number, we calculated a combined pollutant index on premises similar to those used for combined occupational exposures, but with U.S. primary air quality standards rather than threshold limit values as indices of minimal health effects. The combined index exceeded unity in all three towns, suggesting either that total pollutant loads may be excessive even in the sparsely populated town of Lebanon, Connecticut, or, more likely, that the U.S. primary air quality standards have been set at low levels without due regard for additive effects.

Air Pollutants↗

PubMed2005

Does socio-demographic status influence the effect of pollens and molds on hospitalization for asthma? Results from a time-series study in 10 Canadian cities.

PURPOSE: Social status influences asthma morbidity but the mechanisms are not well understood. To determine if sociodemographics influence the susceptibility to ambient aeroallergens, we determined the association between daily hospitalizations for asthma and daily concentrations of ambient pollens and molds in 10 large Canadian cities. METHODS: Daily time-series analyses were performed and results were adjusted for day of the week, temperature, barometric pressure, relative humidity, ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide. Results were then stratified by age, gender, and neighborhood family education and income. RESULTS: There appeared to be age and gender interactions in the relation between aeroallergens and asthma. An increase in basidiomycetes equivalent to its mean value, about 300/m3, increased asthma admissions for younger males (under 13 years of age) by 9.3% (95% CI, 4.8%, 13.8%) vs. 4.2% (95% CI, - 0.1%, 8.5%) for older males. The reverse was true among females with increased effect in the older age group: 2.3% (95% CI, 1.2%, 5.8%) in those under 13 years vs. 7.1% (95% CI, 4.1%, 10.1%) for older females. Associations were seen between aeroallergens and asthma hospitalization in the lowest but not the highest education group. CONCLUSIONS: Our results suggest that younger males and those within less educated families may be more vulnerable to aeroallergens as reflected by hospitalization for asthma.

Adolescent↗

PubMed2005

Statistical interpretation of weekday/weekend differences of ambient gaseous pollutants, vehicular traffic and meteorological parameters in urban region of Kolkata.

An air quality sampling program has been designed and implemented to collect the concentrations of gaseous pollutants (SO2, NO2 and NH3) at weekdays and weekends from a network of three monitoring stations during November 2003 to May 2004 along a populated urban region of Kolkata. Monitoring of ambient SO2 (sulphur dioxide), NO2 (nitrogen dioxide) and NH3 (ammonia) was done once in a week for 24 h at the residential (Kasba) and industrial (Cossipore) sites while 8 h at the commercial (Lalbazar) site. Average ratio of the weekday/ weekend concentrations of SO2, NO2 and NH3 were 1.41, 1.01 and 0.99 at Kasba; 1.33, 1.13 and 1.10 at Cossipore and 1.09, 1.17 and 1.10 at Lalbazar, respectively. Linear regression analysis between SO2 and NO2 showed good (R2 > 0.70) relationship at weekdays in residential and industrial sites. It also showed moderate (R2 > 0.50) relationship in residential site and good (R2 > 0.70) relationship in industrial sites at weekends. In the commercial site, a strong (R2 > 0.90) linear association has been observed between SO2 and NO2 at weekdays and weekends. Daily average vehicular traffic at weekdays was higher than those on weekends. The spearman rank correlation coefficient showed that measured gaseous pollutants have inverse correlation with meteorological parameters (temperature, relative humidity and wind speed) at all the sites, both on weekdays and weekends.

Air Pollutants↗

PubMed1992

Air pollution related respiratory morbidity in central and north-eastern Bombay.

A study of 4 comparable communities in central & northeastern Bombay (2 each) among randomly matched 349 subjects in 1988-9, along with ambient sulfur dioxide (SO2), Nitrogen dioxide (NO2) & suspended particulate matter (SPM) air monitoring was carried out. The levels in winter were higher particularly for SO2 in Parel (upto 584 micrograms) in Maravali; Deonar showed lower pollution. There were inter-area differences for housing, income, residential history but age-sex differences were small; these were reduced by matching. Clinical respiratory symptoms were higher in Parel & Maravali (cough 12% and 11.2%, dyspnoea 17% & 13.3% respectively). Cardiac problems are commoner in Parel (11.0%). Smoker had cough more often but not dyspnoea. Maravali had a high prevalence for headache and eye irritation (9.5%). Those using kerosene suffered more than those using gas (22.2% as compared to 9.2%) Lung functions (FVC, FEVI) were lowest in Parel for males and in Maravali for females. Expiratory flow rates were lower at Dadar and then at Maravali. Despite lower SO2 pollution, Maravali residents suffered equally as in Parel. This may be due to added effect of diesel exhausts (NO2, SPM) or other unmeasured chemicals.

Adolescent↗

PubMed2005

Coarse particulate matter and hospitalization for respiratory infections in children younger than 15 years in Toronto: a case-crossover analysis.

OBJECTIVES: The purpose of this study was to examine the association between ambient air pollution and hospitalization for respiratory infections among children who were younger than 15 years in Toronto during a 4-year period (1998-2001). METHODS: Exposures averaged during periods that varied from 1 to 7 days were used to assess the effects of air pollutants, including thoracic particulate matter (PM10), fine (PM2.5) and coarse (PM10-2.5) particulate matter, carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3), on hospitalization for respiratory infections. A case-crossover design was used to calculate odds ratios for the hospitalization adjusted for daily weather conditions with an incremented exposure corresponding to the interquartile range in air pollution exposures. RESULTS: When particulate matter and gaseous pollutants were mutually taken into account, the effect remained pronounced for PM10-2.5 in both boys and girls. The adjusted odds ratio for 6-day average exposure to PM10-2.5 with an increment of 6.5 microg/m3 was 1.15 (95% confidence interval: 1.02-1.30) for boys and 1.18 (95% confidence interval: 1.01-1.36) for girls. The effect also remained for PM10 in boys and for NO2 in girls. PM2.5, CO, SO2, and O3 showed no significant effects on hospitalization for respiratory infection in both genders when other pollutants were taken into consideration. CONCLUSION: Our study suggested a detrimental effect of relatively low levels of ambient particulate matter and gaseous pollutants, especially coarse particulate matter and NO2, on hospitalization for respiratory infections in children.

Adolescent↗

PubMed1991

Associations of daily mortality and air pollution in Los Angeles County.

We report results of a multiple regression analysis examining associations between aggregate daily mortality counts and environmental variables in Los Angeles County, California for the period 1970 to 1979. Mortality variable included total deaths not due to accidents and violence (M), deaths due to cardiovascular causes (CV), and deaths due to respiratory causes (Resp). The environmental variables included five pollutants averaged over Los Angeles County--total oxidants (Ox), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and KM (a measure of particulate optical reflectance). Also included were three metereological variables measured at the Los Angeles International Airport--temperature (Temp), relative humidity (RH), and extinction coefficient (Bext), the latter estimated from noontime visual range. To reduce the possibility of spurious correlations arising from the shared seasonal cycles of mortality and environmental variables, seasonal cycles were removed from the data by applying a high-pass filter. Cross-correlation functions were examined to determine the lag structure of the data prior to specifying and fitting the multiple regression models relating mortality and the environmental variables. The results demonstrated significant associations of M (or CV) with Ox at lag 1, temperature, and NO2, CO, or KM. Each of the latter three variables were strongly associated with daily mortality but also were highly correlated with one another in the high-frequency band, making it impossible to uniquely estimate their separate relationships to mortality. The results of this study show that small but significant associations exist in Los Angeles County between daily mortality and three separate environmental factors: temperature, primary motor vehicle-related pollutants (e.g., CO, KM, NO2), and photochemical oxidants.

Air Pollutants↗

PubMed2000

Fine particulate air pollution and mortality in 20 U.S. cities, 1987-1994.

BACKGROUND: Air pollution in cities has been linked to increased rates of mortality and morbidity in developed and developing countries. Although these findings have helped lead to a tightening of air-quality standards, their validity with respect to public health has been questioned. METHODS: We assessed the effects of five major outdoor-air pollutants on daily mortality rates in 20 of the largest cities and metropolitan areas in the United States from 1987 to 1994. The pollutants were particulate matter that is less than 10 microm in aerodynamic diameter (PM10), ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide. We used a two-stage analytic approach that pooled data from multiple locations. RESULTS: After taking into account potential confounding by other pollutants, we found consistent evidence that the level of PM10 is associated with the rate of death from all causes and from cardiovascular and respiratory illnesses. The estimated increase in the relative rate of death from all causes was 0.51 percent (95 percent posterior interval, 0.07 to 0.93 percent) for each increase in the PM10 level of 10 microg per cubic meter. The estimated increase in the relative rate of death from cardiovascular and respiratory causes was 0.68 percent (95 percent posterior interval, 0.20 to 1.16 percent) for each increase in the PM10 level of 10 microg per cubic meter. There was weaker evidence that increases in ozone levels increased the relative rates of death during the summer, when ozone levels are highest, but not during the winter. Levels of the other pollutants were not significantly related to the mortality rate. CONCLUSIONS: There is consistent evidence that the levels of fine particulate matter in the air are associated with the risk of death from all causes and from cardiovascular and respiratory illnesses. These findings strengthen the rationale for controlling the levels of respirable particles in outdoor air.

Air Pollutants↗

PubMed1999

Association of ambient air-pollution levels with acute asthma exacerbation among children in Singapore.

BACKGROUND: Air-pollution levels have been shown to be associated with increased morbidity of respiratory diseases. METHODS: Data for ambient air-pollutant levels, meteorologic factors, and hospitalization or emergency room (ER) visits for acute asthma in Singapore children over a 5-year period (1990-4) were obtained and analyzed for associations by time-series methods. RESULTS: Throughout this period, the annual mean and 24-h mean levels for sulfur dioxide (SO2), nitrogen dioxide (NO2), and total suspended particles (TSP) and maximum 1-h daily average for ozone were generally within the air-quality guidelines established by the World Health Organization (WHO). However, positive correlation between levels of each of these pollutants and daily ER visits for asthma was observed in children aged 3-12 years, but not among adolescents and young adults (13-21 years old). The association with SO2 and TSP persisted after standardization for meteorologic and temporal variables. An adjusted increase in 2.9 ER visits for every 20 microg/m3 increase in atmospheric SO2 levels, lagged by 1 day, was observed on days when levels were above 68 microg/m3. With TSP, an adjusted increase of 5.80 ER visits for every 20 microg/m3 increase in its daily atmospheric levels, lagged by 1 day, was observed on days with levels above 73 microg/m3. Similar results were also obtained after controlling for autocorrelation by time-series analysis. CONCLUSIONS: These associations were observed even though the overall levels of all pollutants were generally within the air-quality guidelines established by the WHO. These findings suggest that asthmatic children are susceptible to increased levels of air pollutants, particularly SO2 and TSP, although the ambient levels are generally within "acceptable" ranges.

Acute Disease↗

PubMed1996

Short term respiratory health effects of ambient air pollution: results of the APHEA project in Paris.

STUDY OBJECTIVE: To quantify the short term respiratory health effects of ambient air pollution in the Paris area. DESIGN: Time series analysis of daily pollution levels using Poisson regression. SETTING: Paris, 1987-92. MEASUREMENTS AND MAIN RESULTS: Air pollution was monitored by measurement of black smoke (BS) (15 monitoring stations), sulphur dioxide (SO2), nitrogen dioxide (NO2), particulate matter less than 13 microns in diameter (PM13), and ozone (O3) (4 stations). Daily mortality and general admissions to public hospitals due to respiratory causes were considered. The statistical analysis was based on a time series procedure using linear regression modelling followed by a Poisson regression. Meterological variables, epidemics of influenza A and B, and strikes of medical staff were included in the models. The mean daily concentration of PM13 and daily 1 hour maximum of SO2 significantly affected daily mortality from respiratory causes. An increase in the concentration of PM13 of 100 micrograms/m3 above its 5th centile value increased the risk of respiratory death by 17%. PM13 and BS were also associated with hospital admissions due to all respiratory diseases (4.1% increased risk when the BS level exceeded its 5th centile value by 100 micrograms/m3). SO2 levels consistently influenced hospital admissions for all respiratory diseases, chronic obstructive pulmonary disease, and asthma. Asthma was also correlated with NO2 levels. CONCLUSIONS: These results indicate that even though the relative risk is weak in areas with low levels of pollution, ambient air pollution, and especially particulate matter and SO2, nonetheless require attention because of the number of people exposed and the existence of high risk groups.

Adolescent↗

PubMed2006

Association between maternal exposure to ambient air pollutants during pregnancy and fetal growth restriction.

Previous research demonstrated consistent associations between ambient air pollution and emergency room visits, hospitalizations, and mortality. Effect of air pollution on perinatal outcomes has recently drawn more attention. We examined the association between intrauterine growth restriction (IUGR) among singleton term live births and sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and fine particles (PM2.5) present in ambient air in the Canadian cities of Calgary, Edmonton, and Montreal for the period 1985-2000. Multiple logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for IUGR, based on average daily levels of individual pollutants over each month and trimester of pregnancy after adjustment for maternal age, parity, infant gender, season, and city of residence. A 1 ppm increase in CO was associated with an increased risk of IUGR in the first (OR=1.18; 95% CI 1.14-1.23), second (OR=1.15; 95% CI 1.10-1.19) and third (OR=1.19; 95% CI 1.14-1.24) trimesters of pregnancy, respectively. A 20 ppb increase in NO2 (OR=1.16; 95% CI 1.09-1.24; OR=1.14; 95% CI 1.06--1.21; and OR=1.16; 95% CI 1.09-1.24 in the first, second, and third trimesters) and a 10 mug/m3 increase in PM2.5 (OR=1.07; 95% CI 1.03-1.10; OR=1.06; 95% CI 1.03-1.10; and OR=1.06; 95% CI 1.03-1.10) were also associated with an increased risk of IUGR. Consistent results were found when ORs were calculated by month rather than trimester of pregnancy. Our findings add to the emerging body of evidence that exposure to relatively low levels of ambient air pollutants in urban areas during pregnancy is associated with adverse effects on fetal growth.

Air Pollutants↗

PubMed1999

Effects of ambient air pollution on upper and lower respiratory symptoms and peak expiratory flow in children.

BACKGROUND: Previous epidemiological studies have shown acute effects of increased amounts of ambient air pollution on the prevalence of respiratory symptoms in children with respiratory disorders. We investigated whether children with bronchial hyperresponsiveness (BHR) and relatively high serum concentrations of total IgE (>60 kU/L, the median value) are susceptible to air pollution. METHODS: We collected data from children during three winters (1992-95) in rural and urban areas of the Netherlands. Lower respiratory symptoms (wheeze, attacks of wheezing, shortness of breath), upper respiratory symptoms (sore throat, runny or blocked nose), and peak expiratory flow were recorded daily for 3 months. The acute effects of airborne particulate matter with a diameter of less than 10 microm, black smoke, sulphur dioxide, and nitrogen dioxide were estimated by logistic regression. FINDINGS: 459 (73%) of 632 children had complete data. Of these, 26% had BHR and relatively high (above median) serum total IgE, 36% had no BHR and total IgE of 60 kU/L or less, 15% had BHR and total IgE of 60 kU/L or less, and 23% had a total IgE of more than 60 kU/L but no BHR. In children with BHR and relatively high serum total IgE the prevalence of lower respiratory symptoms increased significantly by between 32% and 139% for each 100 microm/m3 increase in particulate matter, and between 16% and 131% for each 40 microm/m3 increase in black smoke, SO2, or NO2. Decrease in peak expiratory flow of more than 10% in that group was more common with increased airborne particulate matter and black smoke. There were no consistent positive or negative associations between increased air pollution and prevalence of respiratory symptoms or decrease in peak expiratory flow in the other three groups of children. INTERPRETATION: Children with BHR and relatively high concentrations of serum total IgE are susceptible to air pollution. Although our odds ratios were rather low (range 1.16-2.39) the overall effect of air pollution on public health is likely to be substantial since these odds ratios refer to large numbers of people.

Air Pollutants↗

PubMed1998

Association between hospital emergency visits for asthma and air pollution in Valencia, Spain.

OBJECTIVE: To assess the short term effect of concentrations of black smoke, sulphur dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3) in ambient air on emergency room visits for asthma in the city of Valencia, Spain during the period 1994-5. METHODS: Ecological study with time series data and application of Poisson regression. Associations between number of daily emergency visits in a city's hospital and concentrations of air pollutants were analysed taking into account potential confounding factors by the standardised protocol of the air pollution and health: a European approach (APHEA) project. RESULTS: Mean (range) daily number of emergency room visits for asthma was 1 (0-5). Concentrations of all pollutants studied remained within current air quality standards. The association between an increase of 10 micrograms/m3 in ambient air pollution and asthma, measured as a relative risk (RR) of emergency visits, was significant for NO2 24 hour mean (lag 0, RR 1.076, 95% confidence interval (95% CI) 1.020 to 1.134), NO2 hour maximum (lag 0, RR 1.037, 95% CI 1.008 to 1.066), and O3 hour maximum (lag 1, RR 1.063, CI 95% 1.014 to 1.114). The association was not significant for SO2 or for black smoke during the period analysed. The effects were not significantly different for the time of year, cold months (November to April), or warm months (May to October). CONCLUSIONS: Current concentrations of ambient air pollution in Valencia are significantly associated with emergency room visits for asthma. This association is high and more consistent for NO2 and O3 than for particulate matter and SO2 (classic pollutants).

Adolescent↗

PubMed2005

Seasonal variation of air pollution index: Hong Kong case study.

Air pollution is an important and popular topic in Hong Kong as concerns have been raised about the health impacts caused by vehicle exhausts in recent years. In Hong Kong, sulphur dioxide SO2, nitrogen dioxide (NO2), nitric oxide (NO), carbon monoxide (CO), and respirable suspended particulates (RSP) are major air pollutants caused by the dominant usage of diesel fuel by goods vehicles and buses. These major pollutants and the related secondary pollutant, e.g., ozone (O3), become and impose harmful impact on human health in Hong Kong area after the northern shifting of major industries to Mainland China. The air pollution index (API), a referential parameter describing air pollution levels, provides information to enhance the public awareness of air pollutions in time series since 1995. In this study, the varying trends of API and the levels of related air pollutants are analyzed based on the database monitored at a selected roadside air quality monitoring station, i.e., Causeway Bay, during 1999-2003. Firstly, the original measured pollutant data and the resultant APIs are analyzed statistically in different time series including daily, monthly, seasonal patterns. It is found that the daily mean APIs in seasonal period can be regarded as stationary time series. Secondly, the auto-regressive moving average (ARMA) method, implemented by Box-Jenkins model, is used to forecast the API time series in different seasonal specifications. The performance evaluations of the adopted models are also carried out and discussed according to Bayesian information criteria (BIC) and root mean square error (RMSE). The results indicate that the ARMA model can provide reliable, satisfactory predictions for the problem interested and is expecting to be an alternative tool for practical assessment and justification.

Air Pollutants↗

PubMed2005

Assessment of combustion products of medical waste incinerators in Alexandria.

The emissions and ashes from medical waste incinerators might perform a threat to the environment and the public health. The aim of the present work is to evaluate the emissions and ashes of six medical wastes incinerators in six hospitals in Alexandria. Five air pollutants were sampled and analyzed in the emissions comprising smoke, lead, carbon monoxide, sulphur dioxide and nitrogen dioxide . Ash samples were analyzed for bacterial count, volatile substances, lead and cadmium. Shape and color of ash were observed visually. The results of the present study have revealed that all the average values of gases in the six incinerators were within the limits stated in Egyptian environmental law, where as carbonaceous particulate (smoke) averages of the six incinerators have exceeded the maximum allowable limit in the law. On the other hand, lead concentration in emissions were far below the maximum allowable limit in the law. Incinerator No 6 emissions have been significantly higher in CO, NO2, SO2 and smoke concentration than the other five incinerators P<0.001, P<0.0006, P<0.0001, and P<0.002 respectively. There was no significant variation in bacterial count of ash samples at 20 degrees C and 37 degrees C between the six studied incinerators. Volatile substance percentage of ash samples in the six incinerators were much higher than the recommended percentage. There was a highly significant variation between the six incinerators (p<0.005). Lead and cadmium concentrations in ash samples were much higher than those in developed countries, meanwhile, more or less as those in developing countries. It is recommended to state specific realistic emissions limits for medical waste incinerators and to substitute sporadic incinerators in hospitals by two central incinerators in proper places outside the city.

Air Pollutants↗

PubMed1991

Murine respiratory mycoplasmosis: a model to study effects of oxidants.

Previous studies have shown that exposure to nitrogen dioxide at concentrations of 5 and 10 parts per million (ppm) decreases intrapulmonary killing of Mycoplasma pulmonis, and that this decrease is related to increased lung lesions and mortality. The specific objectives of the present study were to titrate the effects of nitrogen dioxide on pulmonary clearance of M. pulmonis, determine the mechanisms by which this organism is killed within the lungs, and determine the target that the nitrogen dioxide affects. Pathogen-free C57BL/6N mice were exposed to 0, 0.5, 1, 2, or 5 ppm of nitrogen dioxide (contamination with other oxides of nitrogen compounds was 5% or less) for four hours and then immediately were exposed to aerosols of viable, radiolabeled M. pulmonis strain UAB CT. One-half of the animals in each group were killed immediately after exposure to the infectious aerosols, and the rest were killed 24 hours later. The amount of radioactivity and the number of viable M. pulmonis were determined for each group. Exposure to less than 5 ppm of nitrogen dioxide had no effect on intrapulmonary killing of M. pulmonis, although exposure to 1 ppm of nitrogen dioxide did increase mechanical removal. We were unable to develop a completely in vitro mycoplasma killing method. However, we were able to demonstrate the in vitro killing of M. pulmonis that had been allowed to associate with alveolar macrophages in vivo. Thus, mouse lungs contain unidentified factors that allow cells to kill M. pulmonis. Furthermore, we obtained evidence that suggests that prior exposure to nitrogen dioxide abrogates killing in these experiments. We also have shown that exposure to nitrogen dioxide does not increase the protein content of bronchoalveolar lavage fluid. Using immunofluorescence, more than 95% of the cells recovered by lavage were macrophages; with double-label immunofluorescence, more than 98% of the cell-associated mycoplasmas were on or in alveolar macrophages. In assessing the cytological parameters of lung lavage cells from mice exposed to nitrogen dioxide, M. pulmonis, or both, we found that both insults affected the viability of recovered macrophages. Viability immediately after exposure as measured by trypan blue exclusion or by fluorescein diacetate uptake, was 89% +/- 4% and 88% +/- 4% in the control group, respectively; 56% +/- 19% and 64% +/- 11% in the group receiving M. pulmonis alone; 23% +/- 7% and 48% +/- 9% in the group receiving nitrogen dioxide alone; and 16% +/- 6% and 25% +/- 6% in the group receiving both M. pulmonis and 10 ppm nitrogen dioxide exposures.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollutants↗

PubMed2003

Screening and genetic manipulation of plants for decontamination of pollutants from the environments.

In this review, we will describe our study on "nitrogen-philic plants", which can grow with nitrogen dioxide (NO2) as the sole nitrogen source, by screening of naturally occurring plants for the assimilation of nitrogen dioxide and genetic manipulation of plants for those genes involved in the primary nitrate metabolism. Finally, we will briefly describe "Green walls with nitrogen-dioxide-philic plants" for decontamination of pollution in urban areas.

Air Pollutants↗