Annual Characteristics, Source Analysis of PM1-Bound Potentially Harmful Elements in the Eastern District of Chengdu, China

Characteristics and Source Analysis of PM1 in a Typical Steel-Industry City, Southwest China

“…Generally, EF values are defined as the ratio of the elements content in a sample to the elements content of the background. In this study, EF values for the PTEs in PM 1 were calculated using Equation ( 1): (1) where C s means measured PTE concentration in PM 1 , C ref means Mn concentration in PM 1 , B s means the measured PTE content in the reference, B ref means Mn content in the background reference [35,[37][38][39][40][41][42][43][44][45][46]. The contents of heavy elements in soil in Panzhihua were taken as the background values [47][48][49][50][51][52][53].…”

“…Before sampling, the filter membranes were combusted in a muffle furnace (SX-8-13, Beijing, China) at 500 • C for 5 h to remove background contaminants. They were placed in a chamber for 48 h under conditions of 50% ± 5% relative humidity and 25 ± 5 • C both before and after sampling [34,35]. Thereafter, the filters were kept refrigerated at −20 • C until subsequent analysis.…”

“…In addition, the reduced rainfall in winter is also favors the accumulation of pollution. Conversely, in summer, solar radiation is strong, the boundary layer tends to break down and atmospheric convection is enhanced [35,55], leading to a reduction in the mass concentration of PM 1 . Overall, the PM 1 mass concentrations are negatively correlated with temperature, relative humidity and wind speed, and positively correlated with atmospheric pressure (Figures S1 and S2).…”