Mercury concentration in fine atmospheric particles during haze and non-haze days in Shanghai, China

Özet

Concentrations of fine particulate mercury (PHg), particulate matter 2.5 mm (PM2.5), and particulatematter 10 mm (PM10) were monitored for the whole year of 2013 in Shanghai, China. The averageconcentrations of PHg were 1270 ± 716 pg/m3 and 341 ± 187 pg/m3 during haze and non-haze daysrespectively. The average PHg concentration throughout the whole year 2013 was 642 ± 616 pg/m3. Itwas observed that PHg concentrations on haze days were 3 times higher than on non-haze days. Theconcentration of PHg on non-haze days in 2013 varied from 0.25 to 0.48 ng/m3. The mean monthly PHgconcentration was highest in December (1.92 ng/m3), while the minimum mean concentration wasobserved in February and August (0.80 ng/m3), and there was a clear seasonal variation: winter (1.67 ng/m3), autumn (1.08 ng/m3), spring (1.02 ng/m3), and summer (1.00 ng/m3) during haze days. The correlationbetween PHg and PM2.5 was strong (r ¼ 0.96 on haze days; r ¼ 0.90 on non-haze days), while thecorrelation between PHg and PM10 was weaker (r ¼ 0.85 on haze days; r ¼ 0.57 on non-haze days). ThePHg concentration on haze days was always higher than on non-haze days, indicating that haze conditionswere accelerating the formation of PHg. The result also indicated that PHg was inclined tocombine with fine particles. The existence of strong correlations between the concentrations of PM2.5,PM10, and PHg indicated the commonality of the contributing sources, such as traffic, industrial emissions,and the combustion of coal.