PubMed · 5573010
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J Murphree. 1971. Air pollution.. https://pubmed.ncbi.nlm.nih.gov/5573010/
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Capturing the spatiotemporal distribution of pollutants in industrial parks remains challenging for regional air quality models because of their coarse resolution (3 km), resulting in uncertainties in local emission quantification. To address this, we developed the Integrated Multiscale Air Quality Modelling System for Industry (IAQMS-Industry), coupling the regional Nested Air Quality Prediction Modelling System (NAQPMS) with a city-scale chemical transport model. This framework integrates point-source locations and Gaussian plume dispersion to simulate particulate matter with a diameter smaller than 2.5 micrometres (PM2.5) at 100 m resolution. Applied to the Beijing Yi Zhuang and Tangshan industrial parks and evaluated against observations. The coupled model achieved a normalized mean bias (NMB) ranging from 3.1 % to 6.2 %, improving upon NAQPMS (-16.9 % to -7.7 %). Spatial analysis revealed that coarse regional grids underestimated the PM2.5​ concentrations at industrial sites by smoothing gradients, whereas IAQMS-Industry successfully resolved spatial patterns. Industrial point emissions accounted for 22.9 %-26.4 % of PM2.5 in the coupled model, which was significantly greater than the regional model estimates of 1.6 %-13.7 %. These findings indicate that regional models overestimate pollutant dispersion processes in industrial parks while underestimating local industrial impacts. By explicitly resolving point-source dynamics and linking them to regional transport, IAQMS-Industry provides a robust tool for designing targeted emission controls in industrial cities and balancing local air quality improvements with minimized regional pollution outflow. This study underscores the necessity of multiscale modelling for accurate source apportionment and informed environmental governance in industrial zones.
Airborne particulate matter (PM) is hypothesized to play a role in increases in asthma prevalence, although a causal relationship has yet to be established. To investigate the effects of real-world PM exposure on airway reactivity (AHR) and bronchoalveolar lavage (BAL) cellularity, we exposed naive mice to a single dose (0.5 mg/ mouse) of ambient PM, coal fly ash, or diesel PM. We found that ambient PM exposure induced increases in AHR and BAL cellularity, whereas diesel PM induced significant increases in BAL cellularity, but not AHR. On the other hand, coal fly ash exposure did not elicit significant changes in either of these parameters. We further examined ambient PM-induced temporal changes in AHR, BAL cells, and lung cytokine levels over a 2-wk period. Ambient PM-induced AHR was sustained over 7 d. The increase in AHR was preceded by dramatic increases in BAL eosinophils, whereas a decline in AHR was associated with increases in macrophages. A Th2 cytokine pattern (IL-5, IL-13, eotaxin) was observed early on with a shift toward a Th1 pattern (IFN-gamma). In additional studies, we found that the active component(s) of ambient PM are not water-soluble and that ambient PM-induced AHR and inflammation are dose- dependent. We conclude that ambient PM can induce asthma-like parameters in naive mice, suggesting that PM exposure may be an important factor in increases in asthma prevalence.
The atmospheric Se levels in Mumbai varied between 0.02 and 1.92 ng m(-3) with a mean concentration of 0.21 ng m(-3). The daily intake of Se by the adult population of Mumbai is 61.9 microg day(-1). Differential pulse cathodic stripping voltammetry (DP-CSV) has been used for the determination of Se in air particulate and food samples. The detection limit of Se using DPCSV was found to be 0.05 ng ml(-1). The reliability of estimation was further assessed through the analysis of standard reference materials (SRMs), tuna fish, animal blood, milk powder and fish tissue obtained from IAEA. The frequency distribution of dietary intake levels of selenium for Mumbai adults showed that approximately 61% of the studied population have a dietary intake of 30-90 microg day(-1). Ingestion was found to be the main route of Se exposure for Mumbai adults. The turn over time of Se through blood is 17 days.