Concentrations of total arsenic and arsenic species in PM 2.5 in Nanjing, China: spatial variations and influences of local emission sources

AbstractThe aim of this study was to assess the spatial variation in the concentrations of total arsenic (Astotal), arsenite (As(III)), arsenate (As(V)), monomethylarsonic acid (MMAs(V)), and dimethylarsinic acid (DMAs(V)) in fine particulate matter (PM2.5) and to explore the influence of local emission sources based on the monitoring data from 18 sampling sites in Nanjing, China. The results showed that the average concentration of Astotal in the PM2.5 was 6.81 ng/m3 in Nanjing, which exceeded the standard limit of 6 ng/m3 in China. As(V) was the dominant species and varied between 71 and 81% of water-extractible As in the PM2.5. The results of the spatial variation coefficients (CVs) showed that Astotal, As(III), and As(V) displayed moderate levels of spatial heterogeneity (CV = 0.23), while DMAs(V) a considerably high level (CV = 0.60). The concentrations of Astotal and As species can be arranged in the following order: urban background ~ urban street< suburban< rural< industrial sampling sites. This pattern was connected to the influence of three local emission sources (industrial source, road traffic, and biovolatilization), which were quantified by multiple linear regression. Results showed that local road traffic sources had the smallest value of standardized regression coefficient (0.26) among these three sources, indicating that local road traffic sources contributed less to the concentration of As in PM2.5 than industrial source emissions and biovolatilizat...
Source: Air Quality, Atmosphere and Health - Category: Environmental Health Source Type: research