Levels Of Respirable Particulate Matter Research Articles

Berberine hydrochloride ameliorates PM2.5-induced pulmonary fibrosis in mice through inhibiting oxidative stress and inflammatory

Elevated levels of respirable particulate matter (PM) have been strongly linked to disease incidence and mortality in population-based epidemiological studies. Berberine hydrochloride (BBR), an isoquinoline alkaloid found in Coptis chinensis, exhibits antipyretic, anti-inflammatory, and antioxidant properties. However, the protective effects and underlying mechanism of BBR against pulmonary fibrosis remain unclear. This study aimed to investigate the protective effect of BBR on lung tissue damage using a mouse model of PM2.5-induced pulmonary fibrosis. SPF grade C57BL/6 mice were randomly assigned to four groups, each consisting of 10 mice. The mice were pretreated with BBR (50 mg/kg) by gavage for 45 consecutive days. A tracheal drip of PM2.5 suspension (8 mg/kg) was administered once every three days for a total of 15 times to induce lung fibrosis. Moreover, the results demonstrated that PM2.5 was found to inhibit the PPARγ signaling pathway, increase ROS expression, upregulate protein levels of IL-6, IL-1β, TNF-α, as well as regulation of gene expression of STAT3 and SOCS3. Importantly, PM2.5 induced lung fibrosis by promoting collagen deposition, upregulating gene expression of fibrosis markers (TGF-β1, FN, α-SMA, COL-1, and COL-3), and downregulating E-cadherin expression. Remarkably, our findings suggest that these injuries could be reversed by BBR pretreatment. BBR acts as a PPARγ agonist in PM2.5-induced pulmonary fibrosis, activating the PPARγ signaling pathway to mitigate oxidative and inflammatory factor-mediated lung injury. This study provides valuable insights for the future prevention and treatment of pulmonary fibrosis.

Exposure to Respirable Particulate Matter and Its Association with Respiratory Outcomes in Beauty Salon Personnel.

We aimed to assess exposure to respirable particulate matter (PM) of beauty salon personnel, identify its determinants and ascertain the associated respiratory effects. We collected 122 full-day respirable PM samples from 12 beauty salons (floor area ranging from 24 to 550 m3, staff from 4 to 8) in Almaty, Kazakhstan, taking 10 samples from each place using a portable SidePak AM520 monitor. We also assessed lifestyle (smoking, etc.), respiratory symptoms and health-related quality of life (HRQL) of the personnel using questionnaires. Out of 11,831 5-min data points, daily median respirable PM concentrations were highly variable and ranged from 0.013 to 0.666 mg/m3 with 8.5-times difference in the median concentrations between the venue with the highest median (0.29 mg/m3) and the least median (0.034 mg/m3). In a multivariate linear regression modelling, ambient PM2.5 concentration was the strongest predictor of daily median respirable PM concentration (beta 2.12; 95% CI 1.89; 2.39), and R2 of the model was 0.63. We also found a positive association of the median respirable PM with respiratory symptoms and seasonal allergy, but not with HRQL. Short-term respirable PM levels in the beauty salons may be very high, but the median concentrations are mainly determined by the ambient air pollution.

Exposure to respirable dust among workers fabricating aluminium trihydroxide-containing synthetic countertops

The aim of this study is to characterize personal exposure of workers to respirable particulate matter (PM) generated in cutting and other fabrication activities when fabricating acryl polymer/aluminium trihydroxide synthetic countertops. We collected 29 personal full-day samples of respirable PM from three workers in a small private workshop. We tested differences between- and within-worker variances of mass concentrations using the Kruskall-Wallis test. We used segmented regression to test the means and medians 15-min interval concentrations changes over time and to identify a breakpoint. Respirable PM concentrations ranged nearly 100-fold, from 0.280 to 25.4 mg/m3 with a median of 2.0 mg/m3 (1-min concentrations from 13,920 data points). There were no statistical difference in daily median or geometric mean concentrations among workers, whereas the concentrations were significantly higher on days with three versus two workers present. The 15-min median concentrations (n = 974 measures) increased until 2.35 h (beta 0.177; p < 0.05), representing a 0.70 mg increase in exposure per hour. This was followed by a plateau in concentrations. The high levels of respirable PM we observed among workers fabricating aluminium trihydroxide-containing synthetic countertops highlight an unmet early prevention need.

Health effects of ambient levels of respirable particulate matter (PM) on healthy, young-adult population

Abstract There is an absence of studies that define the relationship between ambient particulate matter (PM) levels and adverse health outcomes among the young and healthy adult sub-group. In this research, the relationship between exposures to ambient levels of PM in the 10 micron (PM10) and 2.5 micron (PM2.5) size fractions and health outcomes in members of the healthy, young-adult subgroup who are 18–39 years of age was examined. Active duty military personnel populations at three strategically selected military bases in the United States were used as a surrogate to the control group. Health outcome data, which consists of the number of diagnoses for each of nine International Classification of Diseases, 9th Revision (ICD-9) categories related to respiratory illness, were derived from outpatient visits at each of the three military bases. Data on ambient concentrations of particulate matter, specifically PM10 and PM2.5, were obtained for these sites. The health outcome data were correlated and regressed with the PM10 and PM2.5 data, and other air quality and weather-related data on a daily and weekly basis for the period 1998 to 2004. Results indicate that at Fort Bliss, which is a US Environmental Protection Agency designated non-attainment area for PM10, a statistically significant association exists between the weekly-averaged number of adverse health effects in the young and healthy adult population and the corresponding weekly-average ambient PM10 concentration. A least squares regression analysis was performed on the Fort Bliss data sets indicated that the health outcome data is related to several environmental parameters in addition to PM10. Overall, the analysis estimates a .6% increase in the weekly rate of emergency room visits for upper respiratory infections for every 10 μg/m3 increase in the weekly-averaged PM10 concentration above the mean. The findings support the development of policy and guidance opportunities that can be developed to mitigate exposures to particulate matter.

Particulate Air Pollution and Hospital Admissions for Congestive Heart Failure in Seven United States Cities

The association between short-term elevations in ambient particulate air pollution and increased cardiovascular morbidity and mortality is well documented. Ambient particles may also trigger acute decompensation in patients with congestive heart failure (CHF), but this hypothesis has not been evaluated in a systematic manner. This study evaluated the association between daily levels of respirable particulate matter of aerodynamic diameters < or =10 microm (PM10) and the rate of hospitalization from the emergency room for CHF in Medicare recipients (age > or = 65 years) in 7 United States cities from 1986 and 1999. The time-stratified case-crossover design was used to separately estimate the effect of a 10 microg/m3 increase in PM10 in each city. A combined random-effects estimate was then obtained from the city-specific effect estimates. There were 292,918 admissions with primary diagnoses of CHF during the observation period. Overall, a 10 microg/m3 increase in PM10 was associated with a 0.72% (95% confidence interval 0.35% to 1.10%) increase in the rate of admission for CHF on the same day. The effect of PM10 appeared to be less in patients with secondary diagnoses of hypertension. There was no consistent effect modification by age, gender, race, or any other secondary diagnosis evaluated. In conclusion, these results support the hypothesis that elevated levels of particulate air pollution, below the current limits set by the United States Environmental Protection Agency, are associated with an increase in the rate of hospital admission for exacerbation of CHF.

Air Pollution and Hospital Admissions for Ischemic and Hemorrhagic Stroke Among Medicare Beneficiaries

The association between short-term elevations in ambient air particles and increased cardiovascular morbidity and mortality is well documented. Ambient particles may similarly increase the risk of stroke. We evaluated the association between daily levels of respirable particulate matter (aerodynamic diameter < or =10 microm, PM10) and hospital admission for ischemic and hemorrhagic stroke among Medicare recipients (age > or =65 years) in 9 US cities using a 2-stage hierarchical model. In the first stage, we applied the time-stratified case-crossover design to estimate the effect of PM10 in each city. We used a 3-day unconstrained, distributed lag model to simultaneously estimate the effect of PM10 0 to 2 days before the admission day and controlled for meteorological covariates in all of the models. In the second stage, we used random-effects metaanalytic techniques to combine the city-specific effect estimates. Ischemic (n=155,503) and hemorrhagic (19,314) stroke admissions were examined separately. For ischemic stroke, an interquartile range increase in PM10 was associated with a 1.03% (95% CI, 0.04% to 2.04%) increase in admissions on the same day only. Similar results were observed with CO, NO2, and SO2. For hemorrhagic stroke, no association was observed with any pollutant 0 to 2 days before admission. These results suggest that elevations in ambient particles may transiently increase the risk of ischemic, but not hemorrhagic, stroke. Studies with more accurate assessment of timing of stroke onset are necessary to confirm or refute these findings.

Formation of Nitrate and Sulfate in the Plume of Berlin (8 pp)

Secondary inorganic aerosol (SIA), i.e. particulate sulphate (S(VI)), ammonium and nitrate (N(V)), is formed from gaseous precursors, i.e. sulfur dioxide (S(IV)), ammonia and nitrogen oxides, in polluted air on the time-scale of hours to days. Besides particulate ammonium and nitrate, the respective gaseous species ammonia and nitric acid can be formed as well. SIA contributes significantly to elevated levels of respirable particulate matter in urban areas and in strongly anthropogenically influenced air in general. The near-ground aerosol chemical composition was studied at two stationary sites in the vicinity of Berlin during a field campaign in the summer of 1998. By means of analysis of the wind field, two episodes were identified which allow one to study changes within individual air masses during transport, i.e. a Lagrangian type of experiment, with one station being upwind and the other downwind of the city. By reference to a passive tracer (Na+) and estimates on dry depositional losses, the influences of dispersion and mixing on concentration changes can be eliminated from the data analysis. Chemical changes were observed in N(-III), N(V) and S(VI) species. SIA, i.e. N(V) and S(VI), was formed from emissions in the city within a few hours. Furthermore, the significance of emissions in the city was confirmed by the lacking SIA formation in the case of transport around the city. For the two episodes, SIA formation rates could be derived, albeit not more precisely than by an order of magnitude. N(V) formation rates were between 1.4 and 20 and between 1.9 and 59% h(-1) on the two days, respectively, and S(VI) formation rates were >17 and >10% h(-1). The area south of the city was identified as a source of ammonia. The probability of occurrence of situations during which the downwind site (50 km downwind of Berlin) would be hit by an urban plume is > 7.4%. Furthermore, for the general case of rural areas in Germany, it is estimated that there is a significant probability to be hit by an urban plume (>8%, corresponding to >1 month per year) for more than half of these. The S(VI) formation rates are higher than explainable by homogeneous, gas-phase chemistry and suggest the involvement of heterogeneous reactions of aerosol particles. The possible contribution of heterogeneous processes to S(VI) formation should be addressed in laboratory studies. Measurements at more than two sites could improve the potential of Lagrangian field experiments for the quantification of atmospheric chemical transformations, if a second downwind site is chosen in such a way that, at least under particularly stable conditions, measurements there are representative for the source area.

Comparison of indoor air quality in electrified and un-electrified dwellings in rural South African villages.

A feasibility study was undertaken to assess the suitability of South African rural villages due to be electrified, for the purposes of undertaking a large-scale study of the impact of reductions in indoor air pollution on acute lower respiratory infections. As part of the feasibility study, quantitative assessments of indoor air pollution in non-electrified and electrified dwellings were performed. Concurrent measurements were made of levels of respirable particulate matter (RSP-stationary), and carbon monoxide (CO) (personal on children <18 months), as well as a stationary co-located with RSP) over a 24-h period in 52 un-electrified and 53 electrified dwellings. The proportion of dwellings with a detectable 24-h concentration of RSP was significantly higher in un-electrified (48.1%) than electrified dwellings (24.5%) (chi(2) = 6.30 on 1 d.f., P = 0.012). In addition a Kruskal-Wallis test (adjusted for ties) showed that the distribution of RSP differed between un-electrified and electrified areas (Kruskal-Wallis chi(2) = 8.20 on 1 d.f., P = 0.014). In those dwellings where some RSP was detected, the amount was on average higher in the un-electrified areas (mean 162 microg/m(3), median 107 microg/m(3)) than in the electrified areas (mean 77 microg/m(3), median 37.5 microg/m(3)). Stationary (kitchen CO) levels in un-electrified dwellings ranged from 0.36 to 20.95 p.p.m. However, in electrified dwellings, kitchen levels ranged from 0 to 11.8 p.p.m. When mean concentrations of CO were compared between electrified and un-electrified dwellings using a two-sample t-test (on log-transformed data), there was overwhelming evidence (P = 0.0004) that the mean level of log (CO) in the kitchen was higher in the un-electrified areas (1.25 vs. 0.69) and also overwhelming evidence (P < 0.0001) that the mean level of log (CO) on the child was higher in the un-electrified areas (0.83 vs. 0.34). Of importance in terms of both policy and for a potential future large-scale study, is that measurable significant differences in indoor pollutants between electrified and un-electrified dwellings during summer were found in spite of only partial transition to electricity use for cooking in electrified villages. It is estimated that at least two-thirds of all households in the developing world are still primary dependent on biomass fuels and coal. This situation applies to 59% of rural households in South Africa. In the last decade a program of providing electricity to three million homes has been underway in South Africa. Among others this intervention aims to reduce exposure to pollutants from burning biomass fuels and reduce detrimental health effects, especially in young children. This study provides scientific evidence that electrified homes in South African villages have lower levels of air pollution (RSP and CO) relative to their non-electrified counterparts.