Studies on relationships between air pollutants and allergenicity of Humulus Scandens pollen collected from different areas of Shanghai

Pollen pollution and allergy are becoming prominent issues in China.However,few studies on pollinosis have been reported.As an allergen in the atmosphere,allergenic Humulus scandens pollen was collected from four districts of Shanghai,including Wusong(WS),Jiading(KD),Xujiahui(XJH) and Songjiang(SJ).The mass concentrations of SO2,NO2,O3,PM10,and PM2.5(particulate matter with air dynamic diameter less than 10 and 2.5 um,respectively) near the four sampling sites were also recorded during Humulus scandens pollen season.The allergenicity of the Humulus scandens pollen was assessed by using of a rat model and enzyme linked immunosorbent assay(ELISA).Relationships between the allergenicity and air pollutants were correlated.Our results demonstrated that the biological viability of the pollens collected from the four districts exhibited no significant differences.ELISA and dot blotting results further demonstrated that the serum of sensitized rats exhibited much higher immune-reactive response than that of control groups.Western blotting showed that the 15 KD(1 KD=1000 dalton) proteins of Humulus pollen led to the allergic response.The allergenic intensity of Humulus pollen protein from different samples followed the pattern:WS> JD> XJ> SJ.There was a negative relationship between the allergenicity of Humulus pollens and PM10(R=-0.99)/PM2.5(R=-0.73),and a positive relationship with O3(R=0.92).These data clearly showed that PM10 and PM2.5 could enhance Humulus pollen protein release,and 03 could aggravate the allergenicity of the Humulus pollen.

Environmentally persistent free radicals from residential raw coal combustion and association with chemical components

Emerging environmental persistent free radicals(EPFRs),can generate reactive oxygen species(ROS),posing potential exposure risks to human health.Incomplete coal combustion is a major source of EPFRs.Organic carbonaceous fractions are essential and important players in the formation of EPFRs during coal combustion.However,relationship between individual organic carbonaceous and non-carbon fractions with EPFRs in such emissions are not well known.This paper investigated the characteristics of EPFRs discharged from simulated coal combustion.Our results showed that the concentration of EPFRs was major concentrated on PM 1.1(51.66e81.85%),and more easily oxidized by oxygen resulting in producing more oxygen-centered radicals(semiquinone-type)in PM 1.1.The mean of line width(DHp-p)was 5.87±0.41G higher than that of biomass combustion,indicating more free radical species were emitted from coal combustion.Humic-like substances-carbon(HULIS-C)was the major contributor of the for-mation of EPFRs and facilitate the generated of EPFRs.Secondary processes have also contributed to the formation of EPFRs during the coal combustion.Our result also noted that there was no relationship between transition metals and EPFRs,may be due to the variability and complexity of the chemical properties and composition of PM.This is critical for the prediction of geochemical behavior and risk assessment of EPFRs,which can provide basic data to support policy development to address rural air pollutant emissions.

Size distribution of chemical elements and their source apportionment in ambient coarse, fine, and ultrafine particles in Shanghai urban summer atmosphere

Ambient coarse particles （diameter 1.8-10 μm）, fine particles （diameter 0.1-1.8 μm）, and ultrafine particles （diameter 〈 0.1 μm） in the atmosphere of the city of Shanghai were sampled during the summer of 2008 （from Aug 27 to Sep 08）. Microscopic characterization of the particles was investigated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy （SEM/EDX）. Mass concentrations of Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, and Pb in the size-resolved particles were quantified by using synchrotron radiation X-ray fluorescence （SRXRF）. Source apportionment of the chemical elements was analyzed by means of an enrichment factor method. Our results showed that the average mass concentrations of coarse particles, fine particles and ultrafine particles in the summer air were 9.38 ± 2.18, 8.82 ± 3.52, and 2.02 ± 0.41 μg/m3, respectively. The mass percentage of the fine particles accounted for 51.47% in the total mass of PM10, indicating that fine particles are the major component in the Shanghai ambient particles. SEM/EDX results showed that the coarse particles were dominated by minerals, fine particles by soot aggregates and fly ashes, and ultrafine particles by soot particles and unidentified particles. SRXRF results demonstrated that crustal elements were mainly distributed in the coarse particles, while heavy metals were in higher proportions in the fine particles. Source apportionment revealed that Si, K, Ca, Fe, Mn, Rb, and Sr were from crustal sources, and S, Cl, Cu, Zn, As, Se, Br, and Pb from anthropogenic sources. Levels of P, V, Cr, and Ni in particles might be contributed from multi-sources, and need further investigation.

Relationships between chemical elements of PM2.5 and O3 in Shanghai atmosphere based on the 1-year monitoring observation

Mass level of fine particles(PM2.5)in main cities in China has decreased significantly in recent years due to implementation of Chinese Clean Air Action Plan since 2013,however,03 pollution is getting worse than before,especially in megacities such as in Shanghai.In this work,O3 and PM2.5 were continuously monitored from May 27,2018 to March 31,2019.Our data showed that the annual average concentration of PM2.5 and O3(O3-8 hr,maximum8-hour moving average of ozone days)was 39.35±35.74 and 86.49±41.65μg/m3,respectively.The concentrations of PM2.5 showed clear seasonal trends,with higher concentrations in winter(83.36±18.66μg/m3)and lower concentrations in summer(19.85±7.23μg/m3),however,the seasonal trends of O3 were different with 103.75±41.77μg/m3 in summer and58.59±21.40μg/m3 in winter.Air mass backward trajectory,analyzing results of potential source contribution function model and concentration weighted trajectory model implied that pollutants from northwestern China contributed significantly to the mass concentration of Shanghai PM2.5,while pollutants from areas of eastern coastal provinces and South China Sea contributed significantly to the mass level of ozone in Shanghai atmosphere.Mass concentration of twenty-one elements in the PM2.5 were investigated,and their relationships with O3 were analyzed.Mass level of ozone had good correlation with that of Ba(r=0.64,p<0.05)and V(r=0.30,p>0.05),suggesting vehicle emission pollutants contribute to the increasing concentration of ozone in Shanghai atmosphere.

Atmospheric HULIS and its ability to mediate the reactive oxygen species (ROS)： A review

Atmospheric humic-like substances （HULIS） are not only an unresolved mixture of macro- organic compounds but also powerful chelating agents in atmospheric particulate matters （PMs）; impacting on both the properties of aerosol particles and health effects by generating reactive oxygen spedes （ROS）. Currently, the interests of HULIS are intensively shifting to the investigations of HULIS-metal synergic effects and kinetics modeling studies, as well as the development of HULIS quantification, findings of possible HULIS sources and generation of ROS from HULIS. In light of HULIS studies, we comprehensively review the current knowledge of isolation and physicochemical characterization of HULIS from atmospheric samples as well as HULIS properties （hygroscopic, surface activity, and colloidal） and possible sources of HULIS. This review mainly highlights the generation of reactive oxygen species （ROS） from PMs, HULIS and transition metals, especially iron. This review also summarized the mechanism of iron-organic complexation and recent findings of OH formation from HULIS-metal complexes. This review will be helpful to carry out the modeling studies that concern with HULIS-transition metals and for further studies in the generation of ROS from HULIS-metal complexes,