The variation of PM2.5 in different urban functional zones and its impact on human health– a case from an Indian megacity region
摘要
Particulate matter (PM) is considered one of the principal air pollutants that degrade air quality and increase human health risks. Landscape pattern impacts PM2.5, and understanding PM2.5 in response to the landscape pattern is crucial for sustainable urban health. In this study, the influence of landscape configuration and composition PM2.5 using landscape metrics (e.g., percentage of landscape (PLAND), number of patches (NP), patch density (PD), largest patch index (LPI), Shannon’s diversity index (SHDI), contagion (CONTAG), Shannon’s evenness index (SHEI), aggregation index (AI) or total area (TA)) land use data integrating remote sensing in Kolkata megacity region (KMR), Eastern India. The impact of PM2.5 on human health has been assessed based on the questionnaire survey. A correlation and regression analysis were also carried out to assess the relation between PM2.5 and landscape fragmentations and to study the effect of the landscape pattern on PM2.5. A principal component analysis was also carried out to understand the association between PM2.5 and landscape patterns in winter and summer. The results showed that: (i) the PM2.5 in winter was higher than in the summer; (ii) the industrial and educational zones had a higher PM2.5 concentration than the cultural and residential zones (iii) built-up area had a significant impact on PM2.5 concentration in winter; (iv) PD, ED and AI had significant positive correlations with PM2.5 concentration, while SHEI had a significant negative correlation; (v) regression results showed that Land use type (winter and summer) and Landscape pattern (summer), had a higher capacity to predict PM2.5. Vegetation predicted better PM2.5 concentration than built-up in land use type (summer) and Landscape pattern (winter and summer). The findings of this study suggest that land use planning and policies are essential to reducing PM2.5 concentration in cities.