基因污染、生物安全与国际环境保护--《生物安全议定书》与国际环境法的新发展

伴随着转基因技术的发展 ,产生了基因污染 ,现代生物技术效益与危险性并存 ,为了防止基因污染的危害 ,保护地球生物多样性 ,包括中国在内的 70多个国家签署了《生物安全议定书》,《生物安全议定书》主要对转基因活生物体的越境转移即国际贸易的安全性作出了规定 ,这对于国际环境保护的发展具有深远意义 ,作为一个条约 ,它首次将转基因技术的发展与生态环境的保护联系起来 ,并将对各国转基因技术的发展 ,对转基因技术及其产品 (Genetically Modified Organisms,GMO)的国际贸易产生影响 ,从而影响地球生态环境的保护 ,也使国际环境法出现了一个新领域 :转基因技术与生物多样性的国际保护     

Route-to-Route Extrapolation of the Toxic Potency of MTBE

MTBE is a volatile organic compound used as an oxygenating agent in gasoline. Inhalation from fumes while refueling automobiles is the principle route of exposure for humans, and toxicity by this route has been well studied. Oral exposures to MTBE exist as well, primarily due to ground-water contamination from leaking stationary sources, such as underground storage tanks. Assessing the potential public health impacts of oral exposures to MTBE is problematic because drinking water studies do not exist for MTBE, and the few oil-gavage studies from which a risk assessment could be derived are limited. This paper evaluates the suitability of the MTBE database for conducting an inhalation route-to-oral route extrapolation of toxicity. This includes evaluating the similarity of critical effect between these two routes, quantifiable differences in absorption, distribution, metabolism, and excretion, and sufficiency of toxicity data by the inhalation route. We conclude that such an extrapolation is appropriate and have validated the extrapolation by finding comparable toxicity between a subchronic gavage oral bioassay and oral doses we extrapolate from a subchronic inhalation bioassay. Our results are extended to the 2-year inhalation toxicity study by Chun et al. (1992) in which rats were exposed to 0, 400, 3000, or 8000 ppm MTBE for 6 hr/d, 5 d/wk. We have estimated the equivalent oral doses to be 0, 130, 940, or 2700 mg/kg/d. These equivalent doses may be useful in conducting noncancer and cancer risk assessments.     

五道水库污染对延吉市饮用水的影响及其对策

新建的五道水库是延吉市主要的供水水源,其水质对市民身体健康和全市经济持续发展至关重要.然而,由于五道水库区存在自身潜在污染源和水库上游居民区的污染源,因此提出超前防治污染源,建立生态保护区,以保护水库生态系统,使之成为永久性优质水源.     

Microbiological groundwater quality and health indicators in Mexico City

Groundwater quality was evaluated in the southern and western zones of Mexico City, using bacterial indicators and pathogens. Water quality from 40 wells was related to rates of diarrheal disease with 995 individuals interviewed. The focus of this first study on environmental health indicators (EHI) was based on population data (e.g., drinking water supplies and basic sanitation) and displayed using a Geographic Information System (GIS). Sixty percent of the wells monitored comply with the Mexican drinking water standards; however, based on other microbial evidence, 95% of the wells did not provide good quality water for human consumption. No significant differences were detected among hydrogeological zones. When analyzing by microbial indicators, the southern area was shown to be statistically different (p < 0.01) from the western area of the city. The highest rates of diarrheal diseases were detected in the south; the lowest rates were observed in the west. Although wells in the western side of the city appeared to be more contaminated (54%) than in the south (40%), no significant association with health indicators was detected. These preliminary findings suggest ways to improve the potential of EHI, by framing epidemiological data and the use of GIS.     

Impact of unbalanced DIF item proportions on group-specific DIF identification

Differences in type I error and power rates for majority and minority groups are investigated when differential item functioning (DIF) contamination in a test is unbalanced. Typically, type I error and power rates are aggregated across groups, however cumulative results can be misleading if subgroups are affected differently by study conditions. With unbalanced DIF contamination, type I error and power rates are reduced for groups with more DIF items favoring them, and increased for groups with less DIF contamination. Even when aggregated impacts appear small, differing subgroup impacts can result in a larger proportional bias than in the original data.     

Structured expert elicitation about Listeria monocytogenes cross-contamination in the environment of retail deli operations in the United States

Listeria monocytogenes is among the foodborne pathogens with the highest death toll in the United States. Ready‐to‐eat foods contaminated at retail are an important source of infection. Environmental sites in retail deli operations can be contaminated. However, commonly contaminated sites are unlikely to come into direct contact with food and the public health relevance of environmental contamination has remained unclear. To identify environmental sites that may pose a considerable cross‐contamination risk, to elucidate potential transmission pathways, and to identify knowledge gaps, we performed a structured expert elicitation of 41 experts from state regulatory agencies and the food retail industry with practical experience in retail deli operations. Following the “Delphi” method, the elicitation was performed in three consecutive steps: questionnaire, review and discussion of results, second questionnaire. Hands and gloves were identified as important potential contamination sources. However, bacterial transfers to and from hands or gloves represented a major data gap. Experts agreed about transfer probabilities from cutting boards, scales, deli cases, and deli preparation sinks to product, and about transfer probabilities from floor drains, walk‐in cooler floors, and knife racks to food contact surfaces. Comparison of experts' opinions to observational data revealed a tendency among experts with certain demographic characteristics and professional opinions to overestimate prevalence. Experts’ votes clearly clustered into separate groups not defined by place of employment, even though industry experts may have been somewhat overrepresented in one cluster. Overall, our study demonstrates the value and caveats of expert elicitation to identify data gaps and prioritize research efforts.     

Sample Size Allocation for Food Item Radiation Monitoring and Safety Inspection

The objective of this study is to identify a procedure for determining sample size allocation for food radiation inspections of more than one food item to minimize the potential risk to consumers of internal radiation exposure. We consider a simplified case of food radiation monitoring and safety inspection in which a risk manager is required to monitor two food items, milk and spinach, in a contaminated area. Three protocols for food radiation monitoring with different sample size allocations were assessed by simulating random sampling and inspections of milk and spinach in a conceptual monitoring site. Distributions of ¹³¹I and radiocesium concentrations were determined in reference to ¹³¹I and radiocesium concentrations detected in Fukushima prefecture, Japan, for March and April 2011. The results of the simulations suggested that a protocol that allocates sample size to milk and spinach based on the estimation of ¹³¹I and radiocesium concentrations using the apparent decay rate constants sequentially calculated from past monitoring data can most effectively minimize the potential risks of internal radiation exposure.     

Supply chain contamination: An exploratory approach on the collateral effects of negative corporate events

The present work investigates the impact of negative events on supply chain partners. Through a contextualised discussion of the literature on supply chains and on the efficient market hypothesis, it is proposed that negative events negatively impact the market value of suppliers and customers. Following an exploratory approach, 307 companies (21 source companies, 158 suppliers and 128 customers) comprehending 20 cases of environmental disaster, corporate social irresponsibility, operational failure, corporate fraud and corruption were analysed. Results show that in 12 out of the 20 cases investigated supply chain partners indeed had their market value penalised, encompassing, to a greater or lesser degree, all five categories of cases considered. Yet, while both suppliers and customers absorbed the outcomes of negative events, suppliers seem to be at greater risk of sustaining such losses. Likewise, cases in which the source companies were also negatively affected seem to be slightly more prone to cause losses among suppliers and customers. In this sense, the concept of supply chain contamination is coined to address the observed outcomes. The study offers new insights into the applicability of the efficient market hypothesis and contributes to the assessment of the dissemination of negative events in supply chains, a theme that, despite its potential detrimental consequences for firms and stakeholders, has not yet been sufficiently treated in the Management literature.     

Unconventional Gas Development in the USA: Exploring the Risk Perception Issues

Unconventional gas development (UGD) is growing rapidly in the United States. Drawing on insights from risk perception and risk governance theories and recent public opinion surveys, we find that UGD is an emerging technology that is likely to be perceived as risky, even though objective risk assessments suggest that risks are low and controllable through best risk management practices. Perceived risk varies significantly depending on the state and locality but perceptions of risk appear to be increasing as the technology is used more widely in the United States and as organized opponents of the technology intensify their efforts. Risk perceptions are attenuated somewhat because of the perceived benefits of UGD and compensation schemes for individuals and communities. The types of triggering events necessary for large‐scale social amplification and stigmatization have not yet occurred but awareness of UGD is growing and organized opposition has been sufficient to cause prohibitions of UGD in some U.S. states and localities. Additional directions for social science research on public reactions to UGD are recommended.