Much attention is drawn to polycyclic aromatic hydrocarbons(PAHs)as an air pollutant due to their toxic,mutagenic and carcinogenic properties.Therefore,to understand the levels,seasonality,sources and potential health...Much attention is drawn to polycyclic aromatic hydrocarbons(PAHs)as an air pollutant due to their toxic,mutagenic and carcinogenic properties.Therefore,to understand the levels,seasonality,sources and potential health risk of PAHs in two distinct geographical locations at Karachi and Mardan in Pakistan,total suspended particle(TSP)samples were collected for over one year period.The average total PAH concentrations were 31.5±24.4 and 199±229 ng/m^(3) in Karachi and Mardan,respectively.The significantly lower concentration in Karachi was attributed to diffusion and dilution of the PAHs by the influence of clean air mass from the Arabian sea and high temperature,enhancing the volatilization of the particle phase PAHs to the gas phase.Conversely,the higher concentration(^(-)6 times)in Mardan was due to large influence from local and regional emission sources.A clear seasonality was observed at both the sites,with the higher values in winter and post-monsoon due to higher emissions and less scavenging,and lower values during monsoon season due to the dilution effect.Diagnostic ratios and principal component analysis indicated that PAHs in both sites originated from traffic and mixed combustion sources(fossil fuels and biomass).The average total Ba P equivalent concentrations(Ba P eq)in Karachi and Mardan were 3.26 and 34 ng/m^(3),respectively,which were much higher than the WHO guideline of 1 ng/m^(3).The average estimates of incremental lifetime cancer risk from exposure to airborne Ba P eq via inhalation indicated a risk to human health from atmospheric PAHs at both sites.展开更多
基金supported by the Pan-Third Pole Environment Study for a Green Silk Road(Pan-TPE)(No.XDA20040501)National Natural Science Foundation of China(Nos.41705132,41630754)+1 种基金CAS“Light of West China”program and the State Key Laboratory of Cryospheric Science(No.SKLCS-OP-201801)the Chinese Academy of Sciences for providing President’s International Fellowship Initiative(PIFI)for providing grants as Young Staff(No.2020FYC0001)。
文摘Much attention is drawn to polycyclic aromatic hydrocarbons(PAHs)as an air pollutant due to their toxic,mutagenic and carcinogenic properties.Therefore,to understand the levels,seasonality,sources and potential health risk of PAHs in two distinct geographical locations at Karachi and Mardan in Pakistan,total suspended particle(TSP)samples were collected for over one year period.The average total PAH concentrations were 31.5±24.4 and 199±229 ng/m^(3) in Karachi and Mardan,respectively.The significantly lower concentration in Karachi was attributed to diffusion and dilution of the PAHs by the influence of clean air mass from the Arabian sea and high temperature,enhancing the volatilization of the particle phase PAHs to the gas phase.Conversely,the higher concentration(^(-)6 times)in Mardan was due to large influence from local and regional emission sources.A clear seasonality was observed at both the sites,with the higher values in winter and post-monsoon due to higher emissions and less scavenging,and lower values during monsoon season due to the dilution effect.Diagnostic ratios and principal component analysis indicated that PAHs in both sites originated from traffic and mixed combustion sources(fossil fuels and biomass).The average total Ba P equivalent concentrations(Ba P eq)in Karachi and Mardan were 3.26 and 34 ng/m^(3),respectively,which were much higher than the WHO guideline of 1 ng/m^(3).The average estimates of incremental lifetime cancer risk from exposure to airborne Ba P eq via inhalation indicated a risk to human health from atmospheric PAHs at both sites.
