Foliar uptake of airborne metal(loid)s plays a crucial role in metal(loid)accumulation in plant organs and is influ-enced by the size and emission sources of aerosols.Given the high enrichment of toxic metal(loid)s in...Foliar uptake of airborne metal(loid)s plays a crucial role in metal(loid)accumulation in plant organs and is influ-enced by the size and emission sources of aerosols.Given the high enrichment of toxic metal(loid)s in submicron-scale particulates(PM1),this study established a PM1 exposure system to examine airborne metal(loid)accu-mulation and foliar physiological responses in Oryza sativa L.The results showed that the concentrations of Cu,Zn,As,Pb,and Cd in the leaves and grains were influenced not only by the airborne metal(loid)levels but also by the specific nature of the PM1 particles.The quantitative model for PM1-associated Pb entry into leaf tissue indicated that foliar Pb accumulation was primarily driven by particle adhesion,followed by hydrophilic pene-tration and trans-stomatal liquid film migration,accounting for 87%–89%of the total accumulation.The strong hygroscopicity and high Pb activity of PM1 emitted from waste incineration(WI)increased the Pb absorption coefficient via the hydrophilic and liquid film migration pathway.In contrast,the high hydrophobicity of PM1 from coal burning(CB)led to greater retention of Pb on leaf surfaces.Both foliar reactive oxygen metabolism and photosynthesis indices were sensitive to air pollution.Foliar metal(loid)accumulation and airborne PM1 concentration accounted for the variance in physiological responses in rice leaves.Our results also indicated that Pb was the key element in PM1 emissions from both coal burning(CB)and waste incineration(WI)responsible for significant physiological changes in rice leaves.展开更多
Air pollution has become a major problem in urban areas due to increasing industrialization and urbanization.In this study ambient concentrations of PM1 and metal concentrations as well as source contributions were id...Air pollution has become a major problem in urban areas due to increasing industrialization and urbanization.In this study ambient concentrations of PM1 and metal concentrations as well as source contributions were identified and quantified by using Positive Matrix Factorization(PMF)in receptor modeling in the Metropolitan Area of Porto Alegre,Brazil.The PM1 samples were collected on PTFE filters from December 2012 to December 2014 in two sampling sites.Major ion and trace element concentrations were assessed.The average concentrations were 12.8 and 15.2μg/m^(3) for Canoas and Sapucaia do Sul sites,respectively.Major ion contributions of PM1 were secondary pollutants such as sulfate and nitrate.Trace elements,especially Cu,Pb,Zn,Cd,and Ni also made important contributions which are directly associated with anthropogenic contributions.Our results show significantly higher levels in winter than in summer.Most of the PM1 and the analyzed PM species and elements originated from anthropogenic sources,especially road traffic,combustion processes and industrial activities,which are grouped in 7 major contributing sources.A back-trajectory analysis showed that the long-range transport of pollutants was not relevant in relation to the contribution to PM1 and metal concentrations.This work highlights the importance of urban planning to reduce human health exposure to traffic and industrial emissions,combined with awareness-raising actions for citizens concerning the impact of indoor sources.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42077367 and 21677123).
文摘Foliar uptake of airborne metal(loid)s plays a crucial role in metal(loid)accumulation in plant organs and is influ-enced by the size and emission sources of aerosols.Given the high enrichment of toxic metal(loid)s in submicron-scale particulates(PM1),this study established a PM1 exposure system to examine airborne metal(loid)accu-mulation and foliar physiological responses in Oryza sativa L.The results showed that the concentrations of Cu,Zn,As,Pb,and Cd in the leaves and grains were influenced not only by the airborne metal(loid)levels but also by the specific nature of the PM1 particles.The quantitative model for PM1-associated Pb entry into leaf tissue indicated that foliar Pb accumulation was primarily driven by particle adhesion,followed by hydrophilic pene-tration and trans-stomatal liquid film migration,accounting for 87%–89%of the total accumulation.The strong hygroscopicity and high Pb activity of PM1 emitted from waste incineration(WI)increased the Pb absorption coefficient via the hydrophilic and liquid film migration pathway.In contrast,the high hydrophobicity of PM1 from coal burning(CB)led to greater retention of Pb on leaf surfaces.Both foliar reactive oxygen metabolism and photosynthesis indices were sensitive to air pollution.Foliar metal(loid)accumulation and airborne PM1 concentration accounted for the variance in physiological responses in rice leaves.Our results also indicated that Pb was the key element in PM1 emissions from both coal burning(CB)and waste incineration(WI)responsible for significant physiological changes in rice leaves.
文摘Air pollution has become a major problem in urban areas due to increasing industrialization and urbanization.In this study ambient concentrations of PM1 and metal concentrations as well as source contributions were identified and quantified by using Positive Matrix Factorization(PMF)in receptor modeling in the Metropolitan Area of Porto Alegre,Brazil.The PM1 samples were collected on PTFE filters from December 2012 to December 2014 in two sampling sites.Major ion and trace element concentrations were assessed.The average concentrations were 12.8 and 15.2μg/m^(3) for Canoas and Sapucaia do Sul sites,respectively.Major ion contributions of PM1 were secondary pollutants such as sulfate and nitrate.Trace elements,especially Cu,Pb,Zn,Cd,and Ni also made important contributions which are directly associated with anthropogenic contributions.Our results show significantly higher levels in winter than in summer.Most of the PM1 and the analyzed PM species and elements originated from anthropogenic sources,especially road traffic,combustion processes and industrial activities,which are grouped in 7 major contributing sources.A back-trajectory analysis showed that the long-range transport of pollutants was not relevant in relation to the contribution to PM1 and metal concentrations.This work highlights the importance of urban planning to reduce human health exposure to traffic and industrial emissions,combined with awareness-raising actions for citizens concerning the impact of indoor sources.
