Immunity in children with exposure to environmental lead: II. Effects on humoral immunity

Lead has been found to depress the immune system in animal studies at levels far below those responsible for overt toxicity. Literature studies in animal systems most clearly showed an effect of lead on response to a specific immunogenic stimulus. Data are sparse concerning the effects of lead on the immune system in the human population at greatest risk for exposure-children up to six years of age. This portion of the Phase I study reports concentrations of IgG, IgM, IgA, and IgE, as well as antibody titers to the specific antigenic stimuli provided by the vaccines against diphtheria, tetanus, and Rubella. The study population consisted of a group of 193 children, ages 9 months to 6 years, who participate in the WIC (Women, Infants and Children) and Lead Poisoning Prevention Programs in the urban area of Springfield-Greene County Missouri. Blood lead levels ranged from 1 to 50 g dL^–1. Total Ig levels were determined and the data were analysed. No consistent significant differences were observed among the risk categories in the five age groups examined. A single Ig class in each of three age groups showed apparent significant differences among the various risk categories, but these differences were not correlated with blood lead. An analysis of specific antibody titers to diphtheria, tetanus, and Rubella was performed. Regression analyses of current data in Phase I of this study suggest a detrimental effect of lead on the antibody titres to diphtheria and Rubella.     

Declines in organochlorines in eggs of red-breasted mergansers from Lake Michigan, 1977–1978 versus 1990

From 1977–1978 to 1990, concentrations of polychlorinated biphenyls (PCBs) and most organochlorine pesticides declined in eggs of red-breasted mergansers (Mergus serrator) nesting on islands in northwestern Lake Michigan. Total PCBs decreased 60% (from 21 ppm in 1977–1978 to 8.5 ppm in 1990) and p,p-DDE decreased 66% (from 6.5 to 2.2 ppm). Dieldrin decreased only 16% (from 0.82 to 0.69 ppm). In 1990, 79.1% of incubated eggs hatched, which was not significantly different from the 83.5% that hatched in 1977–1978.The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged.     

Interactions between copper and cadmium modify metal organ distribution in mature tilapia, Oreochromis mossambicus

Sexually mature female tilapia were exposed to sublethal concentrations of waterborne Cu and/or Cd over 6 days, and subsequent body concentrations of these metals were determined in several organs. The results show that the distribution of Cu and Cd was metal and organ specific. This is demonstrated, for example, by the observation that in tilapia, Cu exposure did not result in Cu accumulation in the liver, whereas in the intestinal wall, notably high concentrations of Cu and Cd were measured in metal exposed fish. In addition to single metal exposed fish, we also determined Cu and Cd body distribution in Cu?Cd co-exposed fish. The observed interactions in metal accumulation were most pronounced in the organs of fish exposed to low, environmentally realistic, metal concentrations.     

Estimation of volatile organic compounds in Kuwaiti houses after the Gulf war

Interest in indoor air quality is steadily increasing. Exposure to volatile organic compounds (VOCs) is associated with health effects as diverse as childhood respiratory disease, lung cancer and cardiovascular disease. In an effort to assess the environmental impact indoors from possible sources of VOCs, such as (i) open oil lakes, (ii) chemical and petrochemical industries and (iii) indoor pollution from household items, concentrations of aliphatic and aromatic VOCs, comprising n-hexane to n-hexadecane, benzene, toluene, xylene, ethyl benzene, methanol and o-dichlorobenzene, were measured in indoor air samples from seven different cities in Kuwait using a gas chromatograph. The data for the period March to May 1993 are presented. The VOCs, as measured, were surprisingly low and they are below the concentrations set by the American Hygienists Association. However, although the concentration of the estimated VOCs being low, were cumulative effects of them entering the human body and water sources cannot be ruled out.     

Marginal bleaching of thalli of Rhizocarpon as evidence for acid rain in the Norra Storfjället, Sweden

Recent lichen surveys in the foreland of The Syterb?cken glacier reveal that the crustose lichens, principally species of Rhizocarpon section Rhizocarpon, exhibit marginal bleaching, readily distinguishable from normal pigmented forms. The largest elliptical thallus of Rhizocarpon measured 290 mm maximum diameter on a bedrock outcrop beyond the margin of Little Ice Age moraines in the upper Syterb?cken Valley. Many small and large thalli of Rhizocarpon suffered damage to the periphery of individual thalli. We examine here some of the possible hypotheses explaining these occurrences. Among others, these are bedrock lithology, ice crystal blasting, long-term snowbank cover, ultraviolet exposure and acid rain. While at this time none of the possibilities can be ruled out entirely, acid rain would appear to be at least one of the factors involved. Acid rain, which is known to produce a soil pH as low as 3.3 in the field area, appears to provide a high input of H(+) ions that the lichen algal component cannot withstand. However, the lack of similar effects on associated foliose or fruticose forms raises the possibility that perhaps two or more factors specific to the environment of Rhizocarpon are operating.     

用液相催化法和脱硫除尘器脱除烟气中SO_2

在由旋风水膜和两块旋流塔板组成的处理气量为７５０ｍ￣３／ｈ的二级脱硫除尘器中，进行了用含催化剂Ｍｎ￣（２＋）的水溶液吸收ＳＯ_２的扩大试验。结果表明，在确定的条件下，脱硫率达到７３％，板效率为０．２５～０．２８。在同一设备中同时完成除尘与脱硫过程，设备投资少；以水为吸收剂，运行费用低；中性条件下吸收，长期运转不结垢，可靠性高。     

中国黄土元素背景值分异规律研究

报道了中国黄土中40个元素的背景值,并以F、Cr、Mn、Co、Ni、V、Cu、Zn、As、Se、Cd、Pb、Hg等13个元素为例,讨论了其在黄土高原的分布与含量。利用趋势面分析等数理统计方法,揭示了黄土中元素的某些环境地球化学特征及元素背景值的分异规律。结果表明,黄土的元素背景值具有三维的分异特征,黄土的质地及沉积的生物气候环境黄土是影响背景值分异的主要因素。为中国黄土的风成学说提供了佐证。     

Heavy metals in water bodies purified by suspended substrate of rivers

ＩｎｔｒｏｄｕｃｔｉｏｎＨｅａｖｙｍｅｔａｌｓｉｎｗａｔｅｒｂｏｄｉｅｓａｒｅｓｉｇｎｉｆｉｃａｎｔｌｙｄｉｆｆｅｒｅｎｔｆｒｏｍｏｒｇａｎｉｃｐｏｌｌｕｔａｎｔｓｔｈａｔｃａｎｂｅｍｉｃｒｏｂｉｏｌｏｇｉｃａｌｌｙｄｅｇｒａｄｅｄｏｒｄｅｃｏｍｐｏｓｅｄ .Ｇｅｎｅｒａｌｌｙ ,ｔｈｅｙａｒｅｐｕｒｉｆｉｅｄｔｈｒｏｕｇｈｔｈｅｉｒａｄｓｏｒｐｔｉｏｎｏｎｔｏｓｕｓｐｅｎｄｅｄｓｕｂｓｔｒａｔｅｓｉｎｒｉｖｅｒｓ.Ａｄｓｏｒｐｔｉｏｎｏｆｈｅａｖｙｍｅｔａｌｓｏｎｒｉｖｅｒｓｕｓｐｅｎｄｅｄｓｕｂ…     

中国东南沿海大(中)型浅成中低温热液矿床—斑岩型矿床评价的地质准则、成矿模式及其找矿意义

本文总结中国东南沿海高钾钙碱性—双峰式火山岩带中已勘查大中型矿床成矿环境的共性：矿床所处区域构造的部位、成岩与成矿时代、矿床与岩浆成因类型、火山构造及其基底构造控矿性、矿床与爆发角砾岩、矿床与矿化类型叠加与共生、矿化与蚀变的分带往、矿床定位深度与剥蚀深度。作者认为这八点可作为找寻与评价大（中）型矿床的地质准则。通过火山地质与矿床地质统一的研究提出本区晚中生代以火山为中心地热体系的成矿模式。并就三个方面作类比：①与现代火山地热体系成矿作用类比；②以紫金山高硫型浅成低温热液矿床与世界同类型矿床作比较；③与环太平洋其他火山岩带同类型矿床模式作类比．通过建立本区的模式与类比获得进一步找矿中值得重视的一些思路．     

GHG emission reductions and costs to achieve Kyoto target

Emission projection and marginal abatement cost curves (MACs) are the central components of any assessment of future carbonmarket, such as CDM (clean development mechanism) potentials, carbon quota price etc. However, they are products of very complex,dynamic systems driven by forces like population growth, economic development, resource endowments, technology progress and so on. The modeling approaches for emission projection and MACs evaluation were summarized, and some major models and their results were compared.Accordingly, reduction and cost requirements to achieve the Kyoto target were estimated. It is concluded that Annex I Parties‘ total reduction requirements range from 503--1304 MtC with USA participation and decrease significantly to 140--612 MtC after USA‘ s withdrawal. Total costs vary from 21--77 BUSD with USA and from 5--36 BUSD without USA if only domestic reduction actions are taken. The costs would sharply reduce while considering the three flexible mechanisms defined in the Kyoto Protocol with domestic actions‘ share in the all mitigation strategies drons to only 0--16%.