上海市浦东新区大气降水化学组分及其相关性分析

依据上海市浦东新区2010—2015年2个代表性采样点的142份监测数据,对降水中的化学组成及各组分间的相关性进行了分析。结果表明,监测期间单次降雨的pH值为3.85~6.09,平均值为5.09,属硫酸型/硝酸型复合污染酸雨。其中SO_4~(2-)和NO_3~-为主要离子,平均值分别为4.55和3.31 mg/L。通过SPSS统计分析得出,人类生活和生产过程以及海洋源是浦东新区大气降水化学组分的主要来源,但仍存在不同的区域特征。     

南通市某钢丝绳行业集中区降尘中重金属污染状况评价

针对南通市钢丝绳行业集中区重金属污染问题,分析降尘中的铅、镉、铬、铜、镍、铁、锌、锰等重金属含量,并采用污染指数法和地累积指数法对降尘中重金属污染状况进行评价。结果表明,该集中区降尘中重金属污染程度依次为Zn>Pb>Cd>Cu>Fe>Mn>Ni>Cr,铅、锌为主要污染因子,铅、锌污染级别均处于重污染级别。     

对应分析在大气颗粒物源解析中的应用研究

采用对应分析方法定性研究龙岩市大气颗粒物来源问题。结果表明:龙岩市4个监测点位中龙岩市环境监测站的主要污染源为高岭土矿和土壤风沙尘;龙岩学院与闽西职业技术学院的主要污染源为机动车尾气尘、燃煤尘和土壤风沙尘;龙岩师专的主要污染源为燃煤尘、小煤炉尘、水泥成品、水泥厂除尘器集尘和钢铁厂除尘器集尘。该方法能将R型因子分析和Q型因子分析结合起来,综合体现样品和元素之间的关系,为大气颗粒物源解析提供了一种新的途径。     

江苏省水泥制造业经济发展与大气环境变化相关性分析

选取了2001—2014年的相关数据,分析了江苏省水泥制造业的经济发展、资源能源消耗和污染物排放特征,同时对行业经济发展与大气环境污染变化进行了相关性分析。结果表明,2001—2014年,江苏省水泥制造业工业总产值呈现波动增加趋势,工业煤炭消费量呈现波动增加趋势,投入产出比呈现逐年波动上升态势;SO2的排放强度呈现波动下降的趋势,低于全省平均水平;烟粉尘的排放强度波动下降,高于全省平均水平;NOX的排放强度呈现波动上升的趋势,高于全省平均水平;SO2与烟粉尘排放量与GDP均高度呈负相关,回归曲线模拟基本类似U型的左半段,随着GDP的增加,SO2和烟粉尘的排放量呈现下降趋势。     

图们市大气颗粒物中重金属含量及分布特征

采集了图们市2006年秋、冬两季的TSP和PM10样品,采用湿法消解-原子吸收分光光度法测定了其中的铅、镉、饲、锌、铬、铁、锰7种重金属.结果表明,图们市大气颗粒物中重金属含量由高到低的顺序是Fe>Cr>Zn>Pb>Mn>Cu>Cd.多数重金属元素含量冬季高于秋季,在一天之内早晨的重金属浓度也往往高于晚上争中午,说明大气颗粒物的来源包括天然源和人为源.     

2006年秋冬两季图们市大气气溶胶中多环芳烃分布规律

大气气溶胶是目前大多数城市的首要污染物,其中的多环芳烃是对人体健康危害最大的环境污染物之一。通过图们市2006年9月、12月4个采样点的大气气溶胶样品分析,研究了大气气溶胶中多环芳烃的分布规律。采用超声波萃取法提取样品中的多环芳烃,然后对其进行旋蒸浓缩,氮气吹至1ml,用高效液相色谱进行定性和定量分析。实验结果表明,美国EPA优先控制的16种多环芳烃普遍存在于图们市区的大气气溶胶中。图们市不同时空大气气溶胶中多环芳烃的分布具有一定的规律性。     

鞍山市大气尘和金属元素沉降通量及污染特征

通过采集鞍山市11个点位的降尘样品以及土壤样品,用ICP-MS分析了Cu、Mn、Zn、Pb等元素含量,并计算其沉降通量。结果表明,鞍山地区大气降尘的沉降通量为2.92～59.8g/(m2.month),其中鞍钢厂区沉降通量均值为31.6g/(m2.month),分别是周边地区和对照地区的4.72倍和10.5倍。重金属As、Cr、Pb和Cd的沉降通量分别为3.78、45.5、42.8、0.457g/(hm2.month)。降尘中各元素的富集系数为0.29～190,其中Cu、Fe、Zn、Mo、Cd、Pb和Se的富集系数大于10,说明这些元素主要来自于人为源。鞍钢厂区土壤中Cu、Pb、Mn、Zn、Mo、Cd、Ca、Fe和Se的含量较辽宁省土壤背景值高,说明其土壤环境已经受到了人类活动的影响。     

Impact of a smelter closedown on metal contents of wheat cultivated in the neighbourhood

BACKGROUND: The contamination of soils by heavy metals engenders important environmental and sanitary problems in Northern France where a smelter has been located for more than one hundred of years. It has been one of the most important Pb production sites in Europe until its closedown in March 2003. Ore smelting process generated considerable atmospheric emissions of dust. Despite an active environmental strategy, these emissions were still significant in 2002 with up to 17 tonnes of Pb, 32 tonnes of Zn and 1 tonne of Cd. Over the years, the generated deposits have led to an important contamination of the surrounding soils. Previous studies have shown pollutant transfers to plants, which can induce a risk for human and animal health. The objective of this study was to evaluate the consequences of the smelter closedown on the Cd and Pb contents of wheat (grain and straw) cultivated in the area. METHODS: Paired topsoil and vegetable samples were taken at harvest time at various distances to the smelter. The sample sites were chosen in order to represent a large range of soil metal contamination. Sampling was realised on several wheat harvests between 1997 and 2003. 25 samples were collected before the smelter closedown and 15 after. All ears of about 1 m long of two rows were manually picked and threshed in the lab. Similarly, straw was harvested at the same time. Total metal contents in soil and wheat samples were quantified. RESULTS: A negative correlation between metal concentrations in soil and the distance to the smelter was shown. The wheat grain and straw showed significant Cd and Pb contents. The straw had higher metal contents than the grain. During the smelter activity, the grain contents were up to 0.8 mg kg(-1) DM of Cd and 8 mg kg(-1) DM of Pb. For the straw, maximum contents were 5 mg kg(-1) DM of Cd and 114 mg kg(-1) DM of Pb. After the smelter closedown, we observed a very large decrease of Pb in the grain (82%) and in the straw (91%). A smaller decrease was observed for Cd in grain. Despite this improvement, 80% of the studied samples remained non-acceptable for human consumption, according to the European legislation values, due to a high Cd content. DISCUSSION: Results highlighted a difference in metal accumulation in the plant organs as well as a difference in metal uptake. The approach pointed out the importance of atmospheric fallout in the wheat contamination pathways for Pb. The smelter closedown has lead to a decrease of the Pb content in wheat. It is interesting to relate this finding with the lead blood levels in children living close to the smelter. CONCLUSIONS: Those results have confirmed the importance of dust fallout in the plant contamination pathways. Before the closedown, Pb measured in the plant was principally originating from the smelter dust emissions. It raised the question of the sanitary risks for humans and animals living in the surrounding a of the smelter. RECOMMENDATIONS AND PERSPECTIVES: In the literature, very few articles take the dust deposit as contamination pathways for crops into consideration. However, in highly contaminated sites, this pathway can be very important. Thus, it would be worthy studying the uptake of metal contaminants by plants through the foliar system.     

Local to regional emission sources affecting mercury fluxes to New York lakes

Lake-sediment records across the Northern Hemisphere show increases in atmospheric deposition of anthropogenic mercury (Hg) over the last 150 years. Most of the previous studies have examined remote lakes affected by the global atmospheric Hg reservoir. In this study, we present Hg flux records from lakes in an urban/suburban setting of central New York affected also by local and regional emissions. Sediment cores were collected from the Otisco and Skaneateles lakes from the Finger Lakes region, Cross Lake, a hypereutrophic lake on the Seneca River, and Glacial Lake, a small seepage lake with a watershed that corresponds with the lake area. Sediment accumulation rates and dates were established by ²¹⁰Pb. The pre-anthropogenic regional atmospheric Hg flux was estimated to be 3.0 μg m⁻² yr⁻¹ from Glacial Lake, which receives exclusively direct atmospheric deposition. Mercury fluxes peaked during 1971–2001, and were 3 to more than 30 times greater than pre-industrial deposition. Land use change and urbanization in the Otisco and Cross watersheds during the last century likely enhanced sediment loads and Hg fluxes to the lakes. Skaneateles and Glacial lakes have low sediment accumulation rates, and thus are excellent indicators for atmospheric Hg deposition. In these lakes, we found strong correlations with emission records for the Great Lakes region that markedly increased in the early 1900s, and peaked during WWII and in the early 1970s. Declines in modern Hg fluxes are generally evident in the core records. However, the decrease in sediment Hg flux at Glacial Lake was interrupted and has increased since the early 1990s probably due to the operation of new local emission sources. Assuming the global Hg reservoir tripled since the pre-industrial period, the contribution of local and regional emission sources to central New York lakes was estimated to about 80% of the total atmospheric Hg deposition.     

Long-term nitrate increases in two oligotrophic lakes, due to the leaching of atmospherically-deposited N from moorland ranker soils

During the last 50 years nitrate concentrations in Buttermere and Wastwater (Cumbria, UK) have risen significantly, by 70 and 100%, respectively. By estimating contemporary nitrate fluxes in the lakes' catchments and in sub-catchments and comparing them with the fractional areas of different soil types, it is deduced that the surface water nitrate is derived almost entirely from organic-rich ranker soils that have a limited ability to retain atmospherically-deposited nitrogen. Little or no nitrate leaches from the other major soil type, a brown podzol, despite it having a lower C:N ratio (12.0 g g(-1)) than the ranker (17.0 g g(-1)), nor is there much contribution from the small areas of improved (chemically fertilised) grassland within the catchments. Although some nitrate leaching is occurring, total N losses are appreciably smaller than atmospheric inputs, so the catchment soils are currently accumulating between 3 and 4 g N m(-2) a(-1).