The relationship between persistent organic pollutants in maternal and neonatal tissues and immune responses to allergens: A novel exploratory study

BACKGROUND: Modern persistent organic pollutants (POPs) contamination are logical candidates in the investigation of the, as yet, unexplained association between allergic disease and progressive industrialisation. POPs have been detected in human cord blood, placental tissues and breast milk, and the reported association between cord blood IgE levels and cord/placental POP levels has raised concerns about potential immunological effects in early life. METHODS: The initial aim of this study was to determine if POPs were detectable in maternal blood, cord blood, placental tissues, adipose tissue and breast milk samples from randomly selected Western Australian women (n = 31), where allergic disease is epidemic. Gas chromatography was used to detect polychlorinated biphenyl compounds [PCBs] (as Aroclor 1232, 1254, 1260) and organochlorine (OC) pesticides, including p,p'-DDT, p,p'-DDE, hexachlorobenzene (HCB), lindane, heptachlor epoxide, dieldrin and chlordane. Secondly, we assessed the relationship between POP levels detected in vivo and maternal and neonatal responses (cytokine and lymphoproliferation) to allergens and mitogens. RESULTS: Low level POP contamination was detected in adipose tissue and breast milk (but not in cord blood, maternal blood or placental tissues). The most ubiquitous compound found in over 90% of adipose tissues samples was a OC metabolite of DDT, p,p'-DDE (median 0.07 mg/kg; interquartile range [IQR] 0.05-0.12). However, the majority of other OC compounds were not detectable and PCB were not detectable in any samples. The three main residues detected in breast milk were p,p'-DDE (0.003 mg/l; 0.001-0.009), dieldrin (0.001 mg/l; 0.001-0.046) and HCB (0.001 mg/l; 0.001-0.001). These levels are significantly lower than reported over 20 years ago. There were no consistent relationships between POP levels in vivo and maternal or infant responses, with the exception of a significant inverse association (Spearman rank correlation: r = -0.406, p = 0.049) between maternal adipose tissue levels of OC p,p'-DDE and maternal T helper cell Type 1 interferon [IFN] gamma to mitogens. CONCLUSION: This study provides the first evidence (in Australia) since the early 1990's that adipose OC levels have continued to fall. The negligible levels in this randomly selected group are significantly lower than those previously recorded, suggesting that POP contamination (at biologically relevant levels) is not likely to be a major contributing factor in the increasing rates of allergy in Western Australia. However, the relationship between Th1 immune function and OC contamination is consistent with other reports and is worth investigating as a relevant factor in populations where OC contamination is greater.     

Mitigating GHG Emissions in the Humid Tropics: Case Studies from the Alternatives to Slash-and-Burn Program (ASB)

Tropical forest conversion contributes as much as 25% of the net annual CO₂ emissions and up to 10% of the N_2O emissions to the atmosphere. The net effect on global warming potential (GWP) also depends on the net fluxes of greenhouse gases from land-use systems following deforestation. Efforts to mitigate these effects must take into account not only the greenhouse gas fluxes of alternative land-use systems but also the social and economic consequences that influence their widespread adoption. The global alternatives to slash-and-burn program (ASB) investigated the net greenhouse gas emissions and profitability of a range of land-use alternatives in the humid tropics. The analysis showed that many tree-based systems reduced net GWP compared to annual cropping and pasture systems. Some of these systems are also profitable in terms of returns to land and labor. The widespread adoption of these systems, however, can be limited by start-up costs, credit limitations, and number of years to positive cash flow, in addition to the higher labor requirements. Projects that offset carbon emissions through carbon sinks in land use in the tropics might be a means of overcoming these limitations. A synthesis of the findings from this program can provide guidelines for the selection and promotion of land-use practices that minimize net global warming effects of slash-and-burn.     

Principles for retrofitting coal burners for oxy-combustion

Experiments were performed in a 1.5 MW pilot-scale furnace to investigate the differences between air- and oxy-fired flame behavior from a pulverized coal oxy-research burner designed for flexible operating conditions. The flame behavior was characterized by recording video images of the flames and by measuring radiation intensity along the flame length. Various strategies relating air- and oxy-fired operation of the burner primary register were investigated where the oxy-fired burner primary mass, momentum and velocity were matched to the air-fired conditions. Matching either burner primary mass or momentum under oxy-fired conditions with air-fired conditions resulted in a flame stabilized within the quarl. Matching primary velocity with air-fired conditions resulted in a detached flame indicating a delay in flame ignition for the oxyfired conditions. A decrease in primary velocity of 13% was necessary in order to stabilize a flame within the quarl similar to the air-fired case. Additional experiments also showed a flame could be stabilized with no oxygen enrichment of the primary (～3 vol.%, dry O₂ in the primary). Experiments where oxygen was injected at the burner face indicated injection at the boundary of the primary and secondary flow paths strongly attach a flame and injection at the coal rich primary flow path increased the radiative intensity of the flame.     

The relevance of EKC hypothesis in energy intensity real-output trade-off for sustainable environment in EU-27

Environmental Science and Pollution Research - Considering the prevailing wave of global warming and other environmental challenges, which can be attributed to increasing environmental pollution as...     

Release of beryllium from mineral ores in artificial lung and skin surface fluids

Exposure to some manufactured beryllium compounds via skin contact or inhalation can cause sensitization. A portion of sensitized persons who inhale beryllium may develop chronic beryllium disease (CBD). Little is understood about exposures to naturally occurring beryllium minerals. The purpose of this study was to assess the bioaccessibility of beryllium from bertrandite ore. Dissolution of bertrandite from two mine pits (Monitor and Blue Chalk) was evaluated for both the dermal and inhalation exposure pathways by determining bioaccessibility in artificial sweat (pH 5.3 and pH 6.5), airway lining fluid (SUF, pH 7.3), and alveolar macrophage phagolysosomal fluid (PSF, pH 4.5). Significantly more beryllium was released from Monitor pit ore than Blue Chalk pit ore in artificial sweat buffered to pH 5.3 (0.88 ± 0.01% vs. 0.36 ± 0.00%) and pH 6.5 (0.09 ± 0.00% vs. 0.03 ± 0.01%). Rates of beryllium released from the ores in artificial sweat were faster than previously measured for manufactured forms of beryllium (e.g., beryllium oxide), known to induce sensitization in mice. In SUF, levels of beryllium were below the analytical limit of detection. In PSF, beryllium dissolution was biphasic (initial rapid diffusion followed by latter slower surface reactions). During the latter phase, dissolution half-times were 1,400 to 2,000 days, and rate constants were ~7 × 10⁻¹⁰ g/(cm²·day), indicating that bertrandite is persistent in the lung. These data indicate that it is prudent to control skin and inhalation exposures to bertrandite dusts.     

Associations among members of a black-capped chickadee flock

Summary One color-banded black-capped chickadee flock was studied intensively at a winter feeder in Wisconsin. Flock structure was examined by measuring association among flock members in three ways: spatial proximity, temporal association, and association of individuals during flock movements. Additional information was obtained on aggressive interactions at and near the feeder. By midwinter, the strongest attachments were between males and females who subsequently mated; pair attachments strengthened as the breeding season approached. Lower ranked individuals in the dominance hierarchy showed weaker associations with other flock members in early spring than did more dominant individuals. The strong attachment to the mate may have implications for altruistic behavior within the winter flock.     

Assessment of the use of industrial by-products to remediate a copper- and arsenic-contaminated soil

Two water treatment sludges (WTS-A, WTS-B), two red muds (RM), and red gypsum (RG), all rich in iron oxy-hydroxides, were added to a soil highly polluted with As and Cu at 2% (w/w) to reduce metal bioavailability. Because the amendments increased soil pH to approximately 6, a lime treatment to the same pH and an unamended treatment were included for comparison. All the amendments had significant positive effects on the soil microbial biomass and growth of ryegrass (Lolium multiflorum Lam. cv. Avance), but only WTS-A improved lettuce (Lactuca sativa L. cv. Tom Thumb) growth. The mineralization of added ammonium nitrogen was not significantly affected by the treatments, while a physiologically based extraction test (PBET) showed that bioaccessibility of As was low (< 5%) and decreased only in the WTS-A treatment. Concentrations of As in soil pore water and extractable As only decreased in the WTS and RG treatments. In contrast, Cu concentrations in soil pore water and extractable Cu decreased in all treatments, by more than 84% in the WTS, RM, and RG treatments. Non-isotopically exchangeable As and Cu were present in colloids in the soil pore water. Untreated soil had < 4% isotopically exchangeable As and this decreased by approximately 50%, with WTS, RM, and RG. The labile Cu pool represented a large proportion (34%) of the total Cu pool, and the isotopically exchangeable and soluble Cu were strongly correlated with soil pH. Acidification of the treated soils showed that the labile As and Cu both increased in the treated soils compared with untreated soils. The significance of the treatment effects on soil fertility and potential off-site transport of As and Cu to ground water are discussed.     

Resilience and sustainable development: building adaptive capacity in a world of transformations

Emerging recognition of two fundamental errors underpinning past polices for natural resource issues heralds awareness of the need for a worldwide fundamental change in thinking and in practice of environmental management. The first error has been an implicit assumption that ecosystem responses to human use are linear, predictable and controllable. The second has been an assumption that human and natural systems can be treated independently. However, evidence that has been accumulating in diverse regions all over the world suggests that natural and social systems behave in nonlinear ways, exhibit marked thresholds in their dynamics, and that social-ecological systems act as strongly coupled, complex and evolving integrated systems. This article is a summary of a report prepared on behalf of the Environmental Advisory Council to the Swedish Government, as input to the process of the World Summit on Sustainable Development (WSSD) in Johannesburg, South Africa in 26 August 4 September 2002. We use the concept of resilience--the capacity to buffer change, learn and develop--as a framework for understanding how to sustain and enhance adaptive capacity in a complex world of rapid transformations. Two useful tools for resilience-building in social-ecological systems are structured scenarios and active adaptive management. These tools require and facilitate a social context with flexible and open institutions and multi-level governance systems that allow for learning and increase adaptive capacity without foreclosing future development options.     

Stifled stakeholders and subdued participation: interpreting local responses toward Shimentai Nature Reserve in South China

In recent decades, protected-area management in many developing countries has been molded to win the support and participation of local people. Increasingly, research initiatives are undertaken to enhance understanding of the perceptions and attitudes of rural stakeholders. The effectiveness of the expanding protected-area system in China is critically constrained by similar considerations of community mentality. This paper provides an empirical assessment of local responses towards conservation efforts based on a case study of the recently established Shimentai Nature Reserve (SNR) situated in Yingde, Guangdong Province, China. Questionnaire surveys, face-to-face interviews, and group discussions were employed to gauge local residents' knowledge, perceptions, and expectations towards the SNR. The study covered seven villages situated in and around the reserve, grouped into far-zone (floodplain) and near-zone (upland) categories, accommodating Hakka (Han) and minority Yao peoples. Many respondents had inadequate knowledge, understanding, and perceptions of the reserve. Although most respondents welcomed the expected park-related dividends, the most affected near-zone villagers anticipated losses due to restriction on traditional resource-extraction activities in the forest. The local expectations were influenced by place of residence, emigration of rural young, and household affluence. The lack of local participation in management and inadequate dissemination of information posed obstacles to effective conservation. The high expectation of accruing benefits from development projects, including tourism, might be misplaced and might not be realized. The present honeymoon period of positive attitudes could end soon if the hopes remain unfulfilled for too long. The need to win sustained local support and provide alternative means of livelihood is emphasized.