Characteristics of carbonyls and volatile organic compounds (VOCs) in residences in Beijing,China

Volatile organic compounds (VOCs) and carbonyl compounds were measured both indoors and outdoors in 50 residences of Beijing in heating (December, 2011) and non-heating seasons (April/May, 2012). SUMMA canisters for VOCs and diffusive samplers for carbonyl compounds were deployed for 24 h at each site, and 94 compounds were quantified. Formaldehyde, acetone and acetaldehyde were the most abundant carbonyl compounds both indoors and outdoors with indoor median concentrations being 32.1, 21.7 and 15.3 μg·m⁻³, respectively. Ethane (17.6 μg·m⁻³), toluene (14.4 μg·m⁻³), propane (11.2 μg·m⁻³), ethene (8.40 μg·m⁻³), n-butane (6.87 μg·m⁻³), and benzene (5.95 μg·m⁻³) showed the high median concentrations in indoor air. Dichloromethane, p-dichlorobenzene (p-DCB) and toluene exhibited extremely high levels in some residences, which were related with a number of indoor emission sources. Moreover, isoprene, p-dichlorobenzene and carbonyls showed median indoor/outdoor (I/O) ratios larger than 3, indicating their indoor sources were prevailing. Chlorinated compounds like CFCs were mainly from outdoor sources for their I/O ratios being less than 1. In addition, indoor concentrations between two sampling seasons varied with different compounds. Carbonyl compounds and some chlorinated compounds had higher concentrations in the non-heating season, while alkanes, alkenes, aromatic compounds showed an increase in the heating season. Indoor concentration of VOCs and carbonyls were influenced by locations, interior decorations and indoor activities, however the specific sources for indoor VOCs and carbonyls could not be easily identified. The findings obtained in this study would significantly enhance our understandings on the prevalent and abundant species of VOCs as well as their concentrations and sources in Beijing residences.     

Metals in the indoor environment

There is a growing recognition that individual exposures to a broad spectrum of metal, inorganic and organic pollutants exceed those from ambient and in some cases from the vicinity of industry environments. The agents often found in indoor environments are mostly known to be hazardous in high concentrations, but the lower limit of their dose response relationships are poorly defined.

The major sources of metals in indoor environments are cigarette smoke (mainstream and side stream), fuel combustion, house dust and consumer products with arsenic, cadmium, lead and nickel being of primary toxicological potential (i.e. carcinogenic, genotoxic and reproductive development). Aspects of levels and duration of human exposure to these elements in relation to existing body burdens and subsequent bioavailability and interactions are generally poorly known from inhalation sources.

Although the magnitude of indoor health hazards to metallic constituents is not now known, mounting evidence suggests that both identification of agents and the measurement of indoor exposures are critical for a more realistic assessment of the effect of this aspect of air pollution on human health.     

Assesment of disinfection by‐products removal by ozonation coupled with adsorption

This research work was performed to evaluate ozonation and granular activated carbon adsorption processes from the view‐point of controlling the formation of disinfection by products (DBPs). Both the humic acid and raw water were first preozonated and then adsorbed on the activated carbon to assess the potency for removal of total organic carbon (TOC) and DBPs. The disinfection by‐product including THMs and HAAs, in principle, can be successfully removed through a use of the ozonation and granular activated carbon (GAC) adsorption processes. However, in practice dealing with the raw water, it is necessary to introduce the pilot‐plant to obtain the design and operation guidelines for the water treatment plant through the ICA (Instrumentation Control and Automation) program in our future research work.     

Socioeconomic and indigeneity determinants of the consumption of non-timber forest products in Vietnam’s Bu Gia Map National Park

ABSTRACT

Conservation of protected areas requires understanding of the consumption of forest products by rural people who live near protected forests. Socioeconomic factors such as a better education, income, land holding size, have been used to understand the patterns of consumption of non-timber forest products (NTFPs). Ethnicity, and especially whether or not people are indigenous to the forested areas, may also change consumption patterns. In this study we analysed the socioeconomic factors, indigeneity and geographical locations of people living in the buffer zones of Vietnam’s Bu Gia Map National Park to better understand the key determinants of the consumption of NTFPs. We conducted 121 interviews with local households and found that indigeneity, education, family size, and the area of land used were statistically significant in explaining the amount of NTFPs consumed, while indigeneity and area of land used by local people had positive relationships with the diversity (measured in number of categories) of NTFPs consumed by local people. Interestingly, there were statistically significant effects of interactions between the area of land used and indigeneity on the consumption of NTFPs. The amount of these products is important for indigenous people who belong to the groups using small and medium areas of land. The medium land use group consumed significantly fewer categories of NTFPs than the small and large land use groups. This data may help local managers to develop interventions that support biodiversity conservation, promote sustainability of these important resources and improve the social welfare of marginal groups.     

改进的QuEChERS-高效液相色谱法测定水产品中16种多环芳烃

采用改进的QuEChERS,对水产样品进行提取、净化,用高效液相色谱仪-荧光/紫外检测器串联检测,建立了同时测定水产品中16种多环芳烃的高效液相色谱分析方法.样品经乙腈提取,Florisil+C18小柱净化,Waters PAH色谱柱分离,以乙腈-水为流动相进行梯度洗脱,外标法定量.本方法中,16种多环芳烃在各自相应浓度范围内线性关系良好,相关系数不低于0.999,检出限为0.1—3.6μg·kg-1.采用该方法在鲤鱼、对虾和牡蛎中进行加标回收实验,回收率在75.0%—118.2%范围内,相对标准偏差(RSD)为2.6%—13.7%.应用本方法对环渤海湾的水产样品进行了调查分析,发现部分样品中含有PAHs,含量为2.11—147μg·kg-1,为下一步开展相关风险评估工作打下了良好工作基础.     

The occurrence of disinfection by‐products in Taiwan drinking water

In this study, samples were taken from six conventional water treatment plants for disinfection by‐products analysis. Results from the analysis revealed that trihalomethanes (THMs) concentrations in all samples were below regulatory levels (100 μg/L). Although the national standard for haloacetic acids (HAA5) has not yet been promulgated in Taiwan, samples from two water plants contained HAA5 concentrations exceeding the USEPA limit (MCL of HAA5 of Stage 1, 60 μg/L). THMs and HAA5 were found to be the major disinfection by‐products in all water treatment plants. It was noted that the concentration of HAA5 in most samples was higher than that of the trihalomathanes. However, the formation potential of THM (THMFP) was found to be higher than that of HAA (HAAFP). Good correlation also was found between THMFP (or THMFP) and HAA5 (or THMs). In evaluating the performance of the treatment processes, it was found that conventional water treatment processes followed by activated carbon were effective in removing disinfection by‐products (DBPs) from source water with pre‐ozonation. The treatment processes were at their optimum performance in removing contaminants when O₃/TOC₀ was held at 0.75.     

Expert views on sustainability and technology implementation

The role of non-timber forest products in sustaining rural economies of the southern African region has been underestimated because of inadequate policy recognition. As a result, factors affecting the sustainability of these important resources are being undermined. The aim of the paper is to examine trade in two selected NTFPs and implications for sustaining the resource base in Zimbabwe and South Africa. In eastern Zimbabwe, baobab (Adansonia digitata) bark is harvested for craft purposes, but in danger of destruction in the short term as a result of harvesting and trade arrangements. Unless appropriate harvesting and marketing mechanisms including harvesting cycles and adaptive management are adopted, the baobabs and livelihoods of humans will be threatened in the next decade. For wood products from communal woodlands in the South African study, uncontrolled trade poses danger to sustaining the natural woodlands. In both case studies, the role of non-resident NTFP dealers is a source of inevitable threat in promoting sustainable harvesting and trade. Market forces of demand and supply factors are identified as opportunities or threats and presented in a conceptualised framework. Additionally, the NTFP sector management will need to include opportunistic improvement of small-scale agropastoralism.     

上海市大气PM2.5中羰基化合物的研究

利用2,4-二硝基苯肼(DNPH)作为衍生化试剂,高效液相色谱/紫外检测法(HPLC/UV)定量检测上海市大气PM2.5中单羰基和二羰基化合物,共检测出5种单羰基化合物和2种二羰基化合物(乙二醛和甲基乙二醛).单羰基化合物中浓度最高的是甲醛和乙醛,其年平均浓度分别为(1579.47±672.81)ng/m3和(572.02±470.58)ng/m3;二羰基化合物乙二醛和甲基乙二醛的年平均浓度分别为(63.74±54.27)ng/m3和(97.28±39.62)ng/m3.研究发现上海市大气PM2.5中一些羰基化合物具有明显的日变化和季节变化规律:日变化表现为早晚高峰,而季节性变化单羰基化合物是冬天>夏天,二羰基化合物则是夏季>冬季.此外,PM2.5中羰基化合物的浓度还与温度、湿度、质量浓度具有一定的关系.     

PSE-UPLC-MS/MS法测定污泥中9种药物与个人护理品

利用加压溶剂萃取法(PSE)提取、固相萃取法净化并结合超高效液相色谱-串联四极杆质谱仪(UPLC-MS/MS)检测,建立了污水处理厂污泥中7个药剂类别的9种药物与个人护理品(舒必利、咖啡因、美托洛尔、氯霉素、萘啶酸、卡马西平、驱蚊胺、氯贝酸、苯扎贝特)的分析检测方法.在萃取方法中,对加压溶剂萃取的污泥质量和溶剂进行了优化;在净化方法中,对固相萃取柱种类、固相萃取柱容量、洗脱溶剂和洗脱量进行了优选.结果表明,方法检出限(以干质量计,下同)在2.7～65.0 pg/g范围内,加标回收率在67.0%～130%之间,相对标准偏差均小于25%(即标准偏差小于25 μg/L).应用所建立的分析方法,对北京某污水处理厂的脱水污泥进行了测定,9种目标物质含量为nd(未检出)～50.5 ng/g,其中,舒必利、咖啡因、卡马西平、驱蚊胺和氯贝酸在2010年春、夏季2次采样均有检出.      

典型矿冶区周边农业用地农产品安全风险及影响因素

土壤重金属污染所引发的农产品安全风险日趋严重.以湖南省某典型矿冶区周边农业用地为研究区域,通过分析土壤及农产品重金属含量,揭示了研究区域农业用地土壤重金属污染特征及农产品安全风险,并应用主成分分析及相关性分析手段探明了主要影响因素.结果表明,研究区土壤主要重金属污染物为Cd、Cu、Pb和Zn,平均含量分别为9.12、358、303和185 mg ·kg^-1,pH值范围为4.67~7.22,严格管控类别占比达100%;同种农产品对不同重金属元素的富集情况不同,重金属含量总体表现为：Zn>Cu>Pb>Cd,富集系数（BCF）值为：Cd>Zn>Cu>Pb,其中农产品Pb和Cd超标现象较为严重,超标率分别达78%和41%,具有较高的食用安全风险;不同种类农产品对同一种金属元素富集情况总体表现为叶菜类高于薯类和茄果类;农产品重金属含量可以由2个主成分反映,主成分1方差贡献率高达88.0%,主要受土壤重金属影响（P<0.01）;富集特征除受农产品种类影响外,还可由土壤pH值、阳离子交换量（CEC）和有机质（SOM）含量进行调控（r为-0.407~-0.641,P<0.05）.结果表明,研究区农业用地土壤和农产品均存在多种重金属复合污染,农产品安全风险较高,须规避农作物种植,对污染土壤采取一定的修复管控措施以降低相应风险.