Evaluation of Scalp and Pubic Hair as Bioindicators for Estimating Exposure to Lead

Blood lead concentration is still most commonly used to assess the degree of exposure to environmental lead. However, blood lead levels are relatively transient and so tissues such as hair which store lead over longer periods need to be explored as bioindicators of lead toxicity. The results of such an investigation into hair are presented. These results indicate that there are significant differences in scalp-hair levels between the African, East Indian and Chinese racial groups in the multiracial adult population of Trinidad, West Indies. However, no significant differences were found for the pubic hair levels among the three races. The percentage of sulphur or the carbon: sulphur ratios in scalp hair did not influence the scalp-hair lead levels in the general population, although a significant difference in the carbon:sulphur ratios was observed between the African and East Indian racial groups.     

Nutritional quality of phloem sap in relation to host plant-alternation in the bird cherry-oat aphid

Summary. Host alternation in aphids has been attributed to complementary growth of host plants, or more specifically to seasonal changes in the nitrogen quality of the phloem sap. In this report, seasonal fluctuation of free amino acids in phloem of the winter and summer host plants (Prunus padus, bird cherry and Hordeum vulgare, barley) of Rhopalosiphum padi (the bird cherry-oat aphid) were investigated in the context of aphid growth and behaviour. Phloem was collected from the cut stylets of aphids taken from plants that were grown outdoors. The total concentration of amino acids in P. padus phloem increased between bud break and late flush (spring), decreased in mature leaves (summer), and increased again in early senescent leaves (autumn). In H. vulgare, however, amino acid concentration fluctuated less from seedlings to flowering. Spring aphids from P. padus grew rapidly on this host from bud break to late flush, but died on mature and early senescent leaves. Summer aphids from H. vulgare grew as fast on this host as spring aphids did on flush leaves of P. padus. Sexual females grew more slowly than other generations and nearly as well on mature as on early senescent P. padus leaves. As judged by aphid growth and phloem nitrogen quality, P. padus during spring equals the summer host H. vulgare. However, the lower growth rates of R. padi on mature and senescent leaves of P. padus appear only loosely correlated with phloem amino acid concentrations. Therefore, factors influencing aphid nutrition, or ecology, other than seasonal changes in phloem sap amino acid concentration may explain the existence of host alternation in R. padi.     

Speaking of human factors: Emergent meanings in interviews with professional accident investigators

This paper presents a qualitative analysis of the human factor concept, more specifically what it means and includes in everyday professional discourse. It is founded on 10 extensive interviews with professional investigators within the road, maritime and rail administration concerning their practical investigative work. General and specific results are generated of interview contributions using a pragmatic communicative approach and discourse analysis.Results show that human factors is an expression tied to individual professional experience, sparks dissatisfaction and demands specification due to recurring indexicality problems. It tends to be used for negative matters. The specific results, listing eight different meanings, indicate that there is no such thing as a professional usage of the human factor but a spectrum of meanings. The study concludes that the meanings of the human factor (a) always evolve in the dynamic process of producing and understanding language, (b) are context-dependent, and (c) emerge through talk, as one type of discourse. Contrary to ordinary conceptions, there is no simple matter as a human factor that may be used in a routine manner. A non-specific use of the notion may even obscure a course of events and prevent necessary investigation, for example, if the human factor simply replaces a factor such as ‘fatigue’. Although contemporary interdisciplinary research focuses peripheral factors, the idea of individual humans and their erroneous acts has survived – and lives – in the practical world of professional investigators. Empirically deduced meanings need to be continuously highlighted and problematised if theory is to approach everyday professional practice.     

Recycling potential of urban solid waste destined for sanitary landfills: the case of Indaiatuba, SP, Brazil.

The urban solid waste of the city of Indaiatuba (pop. 175 000), located in the state of S?o Paulo, was characterized, focusing on the recycling potential. For this purpose, collected waste was subdivided into 27 items, classified by mass and volume. About 90% of this waste was found to be potentially recyclable and only 10% requiring landfilling. The compostable organic matter, in the form of food and garden waste, both with high moisture content (51 and 41%, respectively), represents 54% in mass and 21% in volume. The most common type of plastic in this waste is high density polyethylene, whose estimated disposal is about 5000kgday(-1). A socio-economic analysis of the waste generation indicates that low-income neighbourhoods discard relatively less packaging and more food waste, shoes and construction debris than middle and high income ones, which may be due to low purchasing power and schooling. Our findings indicate that more aluminium and uncoloured polyethylene terephthalate is discarded in the warmest months of the year, probably due to a greater consumption of canned and bottled drinks.     

Biomass use in chemical and mechanical pulping with biomass-based energy supply

The pulp and paper industry is energy intensive and consumes large amounts of wood. Biomass is a limited resource and its efficient use is therefore important. In this study, the total amount of biomass used for pulp and for energy is estimated for the production of several woodfree (containing only chemical pulp) and mechanical (containing mechanical pulp) printing paper products, under Swedish conditions. Chemical pulp mills today are largely self-sufficient in energy while mechanical pulp mills depend on large amounts of external electricity. Technically, all energy used in pulp- and papermaking can be biomass based. Here, we assume that all energy used, including external electricity and motor fuels, is based on forest biomass. The whole cradle-to-gate chain is included in the analyses. The results indicate that the total amount of biomass required per tonne paper is slightly lower for woodfree than for mechanical paper. For the biomass use per paper area, the paper grammage is decisive. If the grammage can be lowered by increasing the proportion of mechanical pulp, this may lower the biomass use per paper area, despite the higher biomass use per unit mass in mechanical paper. In the production of woodfree paper, energy recovery from residues in the mill accounts for most of the biomass use, while external electricity production accounts for the largest part for mechanical paper. Motor fuel production accounts for 5–7% of the biomass use. The biomass contained in the final paper product is 21–42% of the total biomass use, indicating that waste paper recovery is important. The biomass use was found to be about 15–17% lower for modelled, modern mills compared with mills representative of today's average technology.     

Does the nutrition profile of vitamins, fatty acids and microelements counteract the negative impact from organohalogen pollutants on bone mineral density in Greenland sledge dogs (Canis familiaris)?

There is a great need for understanding the impact from dietary OHCs (organohalogen compounds) on bone mineral composition - and thereby osteoporosis - in especially arctic wildlife such as polar bears (Ursus maritimus) as well as humans. For that purpose, we measured BMD (bone mineral density) by DXA scanning (g/cm(-2)) in 15 age and weight normalized sledge dog (Canis familiaris) bitches and their 26 pups divided into a control group (n=26) given 50-200 g/day clean pork (Suis scrofa) fat and a treated group (n=15) given 50-200 g/day OHC polluted minke whale (Balaenoptera acutorostrata) blubber as main lipid sources. The results showed that BMD increased significantly with age (linear regression: p<0.0001, r(2)=0.83, n=41) while no sex difference was found in the F-generation (two-way ANOVA: all p>0.3). No differences in BMD(femur) or BMD(vertebrae) between exposed and control individuals in the bitch generation were found (linear mixed effect model: both p>0.38). Likewise, no difference between exposed and control subadults and juveniles in the F-generation was found (two-way ANOVA: all p>0.33). Correlation analyses between BMD(femur), BMD(vertebrae) and groups of OHCs, respectively, did not show any statistically significant relationships nor a clear or decreasing trend (Pearson's: p: 0.07-0.78; r: -0.2-0.59; n: 10-18). As the groups were similar regarding genetics, age and sex are the only factors that can explain this observation. Either the pollutants did not have an impact on BMD using the present time frame and OHC concentrations (threshold levels not reached), or the difference in food composition (mainly vitamins and n3 fatty acids) conceal the potential OHC impact on BMD. Such information is important when evaluating the positive and negative health consequences from eating polluted marine species.     

Deconstructing sustainable rubber production: contesting narratives in rural Sumatra

ABSTRACT

The growing demand for natural rubber is increasingly threatening biodiversity and forest ecosystems. Recently, the French Michelin Group started a cooperation with the World Wide Fund for Nature (WWF) to establish environmentally and socially sustainable ‘model’ rubber plantations in Sumatra and Kalimantan, Indonesia. The framing of Michelin’s tyre production as ‘eco-friendly’ and their purported ‘sustainable’ rubber cultivation contradict with statements by villagers living around Michelin’s plantation in Jambi Province, Sumatra, who are reporting environmental destruction and land tenure conflicts. Conceptually, we build on political ecology and critical human geography perspectives to identify conflicts and ambiguities related to sustainability claims, deforestation and dispossession. Empirically, we draw on qualitative research in a village affected by the plantation. We confront and deconstruct the discursive framing of sustainable rubber production with our empirical findings. We show how the plantation restricts access to land and instead of providing additional income, is actually limiting development opportunities.     

Soil carbon sequestration in degraded semiarid agro-ecosystems--perils and potentials

The Kyoto Protocol opens new possibilities for using the biosphere as a carbon sink. Using agro-ecosystems as carbon sinks may be the most appropriate practice from both environmental and socioeconomic points of view. Degraded agro-ecosystems in Africa might benefit significantly from the improved land management that would be part of a carbon sequestration program. There are vast areas of these agro-ecosystems in Africa and their rehabilitation is an urgent matter. We agree with UNEP that there are potentially important synergies to be made between the Convention on Climate Change, the UN Convention to Combat Desertification and the UN Convention on Biodiversity. In this paper, we have investigated the potential for increasing soil carbon content in semiarid agro-ecosystems in the Sudan and found that increasing fallow periods will result in increased soil carbon content and converting marginal agricultural areas to rangeland will restore the carbon levels to 80% of the natural savannah carbon levels in 100 years. The economic gain from a future carbon sequestration program has the potential of a significant contribution to the household economy in these agro-ecosystems.     

贵州梵净山自然保护区大气汞的沉降

以铜仁汞矿为点源，研究对梵净山汞的辐射、沉降及流通影响．在海拔５００ｍ的梵净山定位测定，应用Ｍｏｓｂａｇ方法，评价梵净山Ｈｇ的干湿沉降的累积是１１５μｇ·ｍ－２·ａ－１，干沉降大约占总沉降的５０％，通过测定苔藓生物量和Ｈｇ含量估算Ｈｇ的总沉降量为８５０μｇ·ｍ－２·ａ－１，Ｈｇ的流通量平均为２１０μｇ·ｍ－２·ａ－１，Ｈｇ的总沉降占总流通量８０％．Ｈｇ在梵净山沉降累积随高度变化关系明显，海拔２０００ｍ以下时汞的沉降累积量较大，和苔藓植物指示汞含量变化关系相一致．