Altruism and environmental risks to health of parents and their children

This paper tests an equilibrium condition from a model that incorporates: (1) altruism of parents toward their young children, and (2) household production of latent health risks. The model demonstrates that an altruistic parent's marginal rate of substitution between an environmental health risk to herself and to her child is equal to the ratio of marginal risk reduction costs. Econometric estimates support this prediction based on data from a stated preference survey involving 488 parents of children aged 3–12 years. This outcome implies that parents reallocate family resources to at least partly offset the effectiveness of public programs that aim to reduce their children's environmental risks.     

论有限责任公司股权转让中的法律问题

我国《公司法》对有限责任公司股权转让的规定过于简单,导致司法实践中对股权转让合同的效力难以认定.结合我国法律规定和公司运作实务,对有限责任公司在股权转让过程中产生的法律问题作一些探讨和分析.参8.     

A multi-level characterization method for the assessment of urban ecological risks

Urban ecological risk characterization is the final step in risk assessment and an important foundation upon which risk managers build risk aversion, risk control, and emergency handling strategies. In this study, we reviewed present risk characterization methods and proposed a multi-level characterization method for the assessment of urban ecological risks. The new characterization method consists of four elements: urban ecological risk sources, risk source probabilities, assessment endpoint indicators, and assessment endpoint indicator probabilities. Using this method, results of risk assessments can be organized into different levels of detail to meet different risk management goals.     

Ecological and health risks of DDTs and HCHs in surface water from the upper reaches of the Huaihe River

Based on the available toxicity data and the concentrations of DDTs and HCHs in surface water from the upper reaches of the Huaihe River, overlapping areas of probability density and margin of safety (MOS₁₀) were used to estimate the risk levels of DDTs and HCHs to aquatic organisms. The overlapping areas of α-HCH, γ-HCH, p,p′-DDE, p,p′-DDD, and p,p′-DDT were found to be 9.3 × 10^?5, 4.6 × 10^?3, 4.3 × 10^?2, 2.2 × 10^?2, and 4.2 × 10^?2, respectively. The risks from DDTs were higher than those from HCHs, the risk from α-HCH being the smallest. The MOS₁₀ values of α-HCH, γ-HCH, p,p′-DDE, p,p′-DDD, and p,p′-DDT were 2.6 × 10³, 97, 5.9, 15, and 8.6, respectively, i.e. greater than 1.0, indicating limited overlaps between the distributions of exposure concentrations and of toxicity data, and thus minimal ecological risk. Health risk calculations based on incremental lifetime risks for HCHs and DDTs were conducted to evaluate human cancer risk and non-carcinogenic hazard. The total cancer risks from organochlorine pesticides (OCPs) in the studied area were in the range of 10^?8–10^?7, lower than the baseline value of acceptable risk (10^?6). Non-carcinogenic hazard indices of OCPs ranging from 10^?6 to 10^?5 were much lower than the threshold values (1.0). These results suggest that the water from the upper reaches of the Huaihe River does not pose any health risk for local residents using river water as a source for drinking water.     

Influence of large-spectrum environmental contamination on the micro-meiobenthic assemblages in harbour sediments of the ligurian sea (W Mediterranean)

The concentration of a large spectrum of environmental contaminants (PCBs, PAHs, pesticides and metals) was assessed in surface sediments of two Ligurian harbours (Sanremo and Alassio, NW Mediterranean Sea, Italy) and their relative impact on micro-meiobenthic assemblages was analysed. Concentration, distribution and relative importance of the different contaminants varied considerably between harbours in relation to the different anthropic activities and contamination sources. Results from Principal Component Analysis indicated that high levels of contaminants were typically correlated with low micro-meiobenthic abundance in the sediment. Heavy metals and the organic enrichment were the main factors affecting the distribution and abundance of the bacterial and meiofaunal assemblages in Alassio harbour, whereas hydrocarbons and pesticides played a major role in Sanremo sediments. Neither the bacteria density nor the meiofauna abundance were dependent on sediment grain size, suggesting that micro-meiobenthic parameters may be under the influence of other variables. Our results suggest that high concentrations of contaminants independently from their source or typology are responsible for the impact observed on micro-meiobenthic assemblages in these harbours.     

Human risk assessment of As,Cd, Cu and Zn in the abandoned metal mine site

The cancer risk and the non-cancer hazard index for inhabitants exposed to As, Cd, Cu and Zn in the soils and stream waters of the abandoned Songcheon Au–Ag mine area were evaluated. Mean concentrations of As, Cd, Cu, Pb and Zn in agricultural soils were 230, 2.5, 120, 160, and 164 mg kg⁻¹, respectively. Mean concentrations of As, Cd and Zn of the water in the stream where drinking water was drawn was 246 μg L⁻¹, 161 μg L⁻¹ and 3899 μg L⁻¹, respectively. These levels are significantly higher than the permissible levels for drinking water quality recommended by Korea and WHO. The resulting human health risks to farmers who inhabited the surrounding areas due to drinking water were summarized as follows: (1) the non-cancer health hazard indices showed that the toxic risk due to As and Cd in drinking water were 10 and 4 times, respectively, greater than those induced by the safe average daily dosages of the respective chemicals. (2) the cancer risk of As for exposed individuals through the drinking water pathway was 5 in 1000, exceeded the acceptable risk of 1 in 10,000 set for regulatory purposes.     

Exposure to Selected Heavy Metals Through Water Ingestion in an Area Under the Influence of Tanneries

This study evaluated the potential toxicological risk posed to human health due to the exposure to heavy metals by water ingestion in an area affected by tanneries – the Cadeia-Feitoria hydrographic basin (Brazil). River water was collected at 10 sites, every 3 months, from July 1999 to April 2000. After acid digestion, total metal concentration was determined by inductively coupled plasma optical emission spectrometry (Cd, Cu, Cr, Ni, Zn), flame atomic absorption (Al, Fe, Pb, Mn), or cold vapor atomic absorption spectrometry (Hg). Cr(VI) was complexed with diphenyl-carbazide and detected by UV–vis spectrometry. In order to quantify the risk of exposure, the risk assessment methodology employed by the Environmental Protection Agency of the United States was applied at a screening level. The assumed scenarios included extreme exposure patterns (ingestion of untreated water, conversion of Cr(III) to Cr(VI), temporal peaks of pollution). Fe, Al, Cd, Hg, and Pb were not included in the risk analysis, since they showed a low toxicity potential or were undetected in the samples. The selected metals presented Hazard Quotients < 1, in the following order of increasing risk: Cu < Cr(III) < Zn < Ni < Mn < Cr(VI). Hazard indexes, representing the additive effect of contaminants, were also low in the basin (< 1), but comparatively increased in the lower reach of Feitoria and Cadeia Rivers. Although noncarcinogenic risk levels did not suggest possible adverse toxicological effects to the human population, a considerable deviation from background conditions was observed downstream the area where tanneries are mainly located.     

Food web structure affects the extinction risk of species in ecological communities

This paper studies the effect of food web structure on the extinction risk of species. We examine 793 different six-species food web structures with different number, position and strength of trophic links and expose them to stochasticity in a model with Lotka–Volterra predator–prey dynamics. The characteristics of species (intrinsic rates of increase as well as intraspecific density dependence) are held constant, but the interactions with other species and characteristics of the food web are varied.     

Temporal dynamics of arsenic uptake and distribution: food and water risks in the Bengal basin

Abstract

Contaminated food chain is a serious contender for arsenic (As) uptake around the globe. In Nadia, West Bengal, we trace possible means of transfer of As from multiple sources reaching different trophic levels, and associated seasonal variability leading to chronic As uptake. This work considers possible sources-pathways of As transfer through food chain in rural community. Arsenic concentration in groundwater, soil, rice, and vegetable-samples collected detected in different harvest seasons of 2014 and 2016. Arsenic level in shallow groundwater samples ranged from 0.1 to 354?µg/L, with 75% of the sites above the prescribed limit by WHO (10?µg/L) during the boro harvest season. High soil As content (～20.6?mg/kg), resulted in accumulation of As in food crops. A positive correlation in As conc. with increase over period in all sites indicating gradual As accumulation in topsoil. Unpolished rice samples showed high As content (～1.75?mg/kg), polishing reduced 80% of As. Among vegetables, the plant family Poaceae with high irrigation requirements and Solanaceae retaining high moisture, have the highest levels of As. Contaminated animal fodder (Poaceae) and turf water for cattle are shown to contaminate milk (0.06 to 0.24?µg/L) and behoves strategies, practices to minimize As exposure.     

Use of environmental isotopes and hydrochemistry as indicators for the origin of groundwater resources in El Dabaa area,northwestern coastal zone of Egypt

The EI-Dabaa area is located on the northwestern coastal zone of Egypt and is considered to be one of the most important regions for land reclamation and agriculture. In addition, it has been selected as a potential site for constructing Egypt's first nuclear power plant.In April 1989, 14 groundwater samples were collected from the area as well as collecting samples from the Mediterranean sea and from local rainwater. These samples were subjected to chemical and environmental isotope analyses. The results of the analyses for stable isotopes (oxygen-18 and deuterium) indicate that the main recharge source of the groundwater in El-Dabaa is the local precipitation during the rainy season. Variation of the environmental tritium content as well as in the chemical composition of both major cations (Na,K,Ca,Mg) and major anions (Cl,SO₄,HCO₃) between different groundwaters in the studied area reflect the high degree of inhomogeneity of the aquifer and different recharging conditions due to permeability of the water bearing formation.The chemical water type of the El-Dabaa groundwater is sodium sulphate (Na₂SO₄) and the SAR values illustrate the suitability of these groundwaters for agricultural purposes.     

Population level effects of reduced fecundity in the fish species perch (Perca fluviatilis) and the implications for environmental monitoring

A 40% reduction in relative gonad size in perch (Perca fluviatilis) has been observed over that past two decades at the Swedish national reference site Kvädöfjärden. This biomarker response could be interpreted as a reduction in fecundity and increased risk of local extinction. However, abundance estimates from the same area has not provided any evidence of a reduction in population size. In the present study, a matrix population model was developed to investigate if a reduction in fecundity can be expected to have long term effects on population viability for perch and to evaluate the probability to detect such effects through abundance estimates. The model was parameterized from 17 years of population data from Kvädöfjärden as well as from other studies on perch. The model included density dependence and environmental stochasticity. The results indicated that a reduction in fecundity that is in level with the observed reduction in relative gonad size in Kvädöfjärden will cause a substantial risk for local extinction. The risk that the population will fall below 20% of the carrying capacity within 50 years is 44% when the fecundity is reduced by 40%. However, due to variability in abundance measurements it will take some time before a reduction in gonad size leads to statistically significant effects on the population. If the fecundity is reduced by 40% successively over a 10-year period, the probability to detect this through abundance estimates within 10 years is less than 50%. The results of the present study clearly show that relevant biomarkers have an important role in environmental monitoring as early warning signals, preferably in combination with measurements at higher levels of biological organization.     

Achieving environmental goals in a world of trade and hidden action: the role of trade policies and eco-labeling

Importing countries often resort to trade policies and consumer actions in order to reduce negative environmental impacts of the products they consume. Traditionally, these policies were non-discriminatory, i.e., they treated all imports equally, without considering the actual damages caused by the product. More recently, there is a trend towards process-discriminatory policies which attempt to discriminate against environmentally unsound imports while encouraging sound alternatives. We develop a theoretical model of the consuming country's optimal trade policy, allowing for asymmetric information and costly monitoring, and analyze what type of policy is preferable under what conditions.     

Distribution,enrichment, accumulation and potential ecological risks of mercury in the sediments of Kaohsiung Harbor,Taiwan

The distribution, enrichment, accumulation and potential ecological risks of mercury (Hg) in the surface sediments of Kaohsiung Harbor, Taiwan, were investigated. Sediment samples from 20 locations throughout Kaohsiung Harbor were collected quarterly from 2006 to 2011, and characterised for mercury, aluminium, water content, organic matter, total nitrogen, total phosphorous, total grease and grain size. The results showed that Hg concentrations varied from 0.06–6.73 mg kg^?1 with an average of 0.54±0.71 mg kg^?1. The spatial distribution of Hg reveals that the Hg concentration is relatively higher in the river mouth regions, especially at the Love River and Canon River mouths from where it gradually diminishes toward the harbour entrance region. The results from the enrichment factor and geo-accumulation index analyses reveal that the sediments near the Love River and Canon River mouths experience severe enrichment and strong accumulation of Hg that originates from upstream sources of pollution. The assessment of biological effects indicates that concentrations of 92.5% Hg found in the sediment are higher than effects range low, implying that the harbour sediments may cause an adverse impact on aquatic lives. The results of a potential ecological risk index indicate that the sediment has higher to serious levels of ecological potential risks.     

Ecological risks of polycyclic aromatic hydrocarbons found in coastal sediments along the northern shores of the Bohai Sea (China)

The total concentrations of 16 United States Environmental Protection Agency (US EPA)-listed polycyclic aromatic hydrocarbons (PAHs) found in coastal and estuarine sediments along the northern shores of the Bohai and Yellow Seas, China, at any study location varied from 0.236 to 8.34 nM g^?1 dry weight (dw). For a given PAH, concentrations varied by one to two orders of magnitude. Ecological risk assessments based on biota–sediment accumulation factors (BSAFs) indicated that the potential ecological hazard of PAHs in the sediments was limited. The average total sediment PAH concentrations were less than the effects range low, indicating that PAHs currently present in the sediments were not harmful to aquatic organisms. The estimated PAH concentration in the aquatic organisms was 0.223 nM g^?1 and posed a limited threat to human health via biological concentration from sediment to harvest of the sea. Assuming no additional PAH inputs, 99% of the 16 PAH molecules currently present in the sediments would be degraded in 40 years.     

A multi-objective optimization approach to allocate environmental flows to the artificially restored wetlands of China's Yellow River Delta

In this paper, a multi-objective optimization model has been developed for allocating freshwater to meet the environmental flow requirements of the restored wetlands in the Yellow River Delta, China. The model seeks a rational balance among appropriate water allocation for the wetlands, a healthy ecosystem, and optimum economic returns for the humans that use the wetlands to earn their livelihood, with the degree of ecosystem health represented by the difference between actual and ideal water levels. And then a holistic method has been used for satisfying multiple objectives to avoid the problem of decision-maker subjectivity, and then solved the resulting optimal allocation model for environmental flows of the wetlands using a genetic algorithm. With water from the Yellow River as the source, the model shows how the optimal monthly water release into the restored wetlands can be achieved in dry, average, and wet years. Using the model, 20-56% reductions in water use could be achieved compared with the current pattern of water release, and the optimal water level in each month would coincide better with the ideal value based on an indicator plant community (reeds). The results of the study demonstrate the capability of the multi-objective programming model to optimize ecological water allocation and management for the wetlands of the Yellow River Delta.     

Modeling water and soil quality environmental impacts associated with bioenergy crop production and biomass removal in the Midwest USA

The removal of corn stover or production of herbaceous crops such as switchgrass (Panicum virgatum) or big bluestem (Andropogon gerardii) as feedstocks for bioenergy purposes has been shown to have significant benefits from an energy and climate change perspective. There is potential, however, to adversely impact water and soil quality, especially in the United States Corn Belt where stover removal predominantly occurs and possibly in other areas with herbaceous energy crops depending upon a number of geo-climatic and economic factors. The overall goal of this research was to provide a thorough and mechanistic understanding of the relationship between stover and herbaceous crop production management practices and resulting range of impacts on soil and water quality, with a focus on eastern Iowa, USA. Comparisons of the production of herbaceous bioenergy crops to continuous corn (Zea mays L.) and corn-soybean (Glycine max L.) rotations on five different soils representative of the region were performed. Indices for total nutrient (nitrogen and phosphorus) loss to surface water and groundwater, total soil loss due to water and wind erosion, and cumulative soil carbon loss were derived to assess long-term sustainability. The Agricultural Policy/Environmental eXtender (APEX) agroecosystem model was used to quantify the sustainability indices and to generate sufficient data to provide a greater understanding of variables that affect water and soil quality than previously possible. The results clearly show the superiority of herbaceous crop production from a soil and water quality perspective. They also show, however, that compared to traditional cropping systems (e.g., corn-soybean rotations with conventional tillage), soil and water quality degradation can be reduced under certain conditions at the same time stover is removed.     

三种典型渔药对大型溞(Daphnia magna)的急性毒性及其关键环境影响因子分析

测试了三种典型渔药三氯异氰尿酸(Trichloroisocyanuricacid,TCCA)、叔丁基对羟基茴香醚(Butylatedhydroxyanisole,BHA)、盐酸环丙沙星(Ciprofloxacinhydrochloride,CPFX)对大型(Daphniamagna)的急性毒性。结果表明,对于大型的毒性由大到小的顺序为:三氯异氰尿酸,叔丁基对羟基茴香醚,盐酸环丙沙星,48hLC50分别为0.19mg·L-1,3.15mg·L-1和135.15mg·L-1。通过三因素三水平正交试验分析了主要环境因子pH值、硬度、腐殖酸对三种渔药对大型毒性的影响,发现pH显著影响TCCA的毒性,硬度显著影响CPFX的毒性,而BHA毒性受环境因素影响不显著。     

Application of k-means clustering to environmental risk zoning of the chemical industrial area

The homogeneous risk characteristics within a sub-area and the heterogeneous from one sub-area to another are unclear using existing environmental risk zoning methods. This study presents a new zoning method by determining and categorizing the risk characteristics using the k-means clustering data mining technology. The study constructs indices and develops index quantification models for environmental risk zoning by analyzing the mechanism of environmental risk occurrence. We calculate the source risk index, air risk field index, water risk field index, and target vulnerability of the study area with Nanjing Chemical Industrial Park using a 100 m - 100 m mesh grid as the basic zoning unit, and then use k-means clustering to analyze the environmental risk in the area. We obtain the optimal clustering number with the largest average silhouette coefficient by calculating the average silhouette coefficients of clustering at different k-values. The clustering result with the optimal clustering number is then used for the environmental risk zoning, and the zoning result is mapped using the geographic information system. The study area is divided into five sub-areas. The common environmental risk characteristics within the same sub-area, as well as the differences between sub- areas, are presented. The zoning is helpful in risk management and is convenient for decision makers to distribute limited resources to different sub-areas in the design of risk reducing intervention.