Arsenic poisoning in groundwater: health risk and geochemical sources in Bangladesh

Of the 2508 water samples analyzed in 10 districts of Bangladesh, 51%, on an average, contained arsenic levels of 0.05 to 2.50 mg/l. 95% of nail, 96% of hair, and 94% of urine samples contained arsenic above the normal level. Approximately 3.58 million people out of a total of 17.92 million who are drinking water containing arsenic levels >0.20 mg/l are potentially exposed to high risk of health hazard. Eight thousand and five hundred arsenic patients are identified; they are suffering from various skin lesions, gangrene in leg, skin, lung, bladder, liver, and renal cancer. A big portion of the total population is highly vulnerable to various internal cancers. Lowest arsenic concentration in drinking water producing dermatological disease is found to be 0.103 mg/l. However, the exposure time to develop arsenicosis varies from case to case reflecting its dependence on arsenic level in drinking water and food, nutritional status, genetic variant of human being, and compounding factors. This study has determined the high intensity of fluorescent humic substances in drinking water containing elevated concentrations of arsenic and very low concentrations of heavy metals. The synergistic/antagonistic effect of fluorescent compounds present in drinking water may aggravate the toxicity of arsenic. Geochemical study suggests that arsenic may be released from both reductive dissolution of Fe and Mn (oxy)hydroxide and microbial oxidation of organic matter.     

甲撑二苯基二异氰酸酯(MDI)生产过程中危险有害因素及对策措施

甲撑二苯基二异氰酸酯 (MDI)生产过程中涉及到了多种危险有害因素。笔者通过对国内现役MDI生产装置进行调研 ,同时结合国内外其他涉及光气生产厂家的情况 ,分析并指出了生产过程中可能出现的危险有害因素 ,从而提出了相应的对策措施     

论我国重大危险源辨识标准

简要介绍了国外重大危险设施的辨识标准研究情况,并结合我国重大危险源普查试点工作的初步辨识标准,以及几个试点城市普查的数据分析,提出了我国重大危险源辨识最小标准的建议     

Interpretation of heavy metal data from mussel by use of multivariate classification techniques

Different strategies of multivariate analysis of metals concentrations (Mn, Fe, Ni, V, Co, Cu, Cd, Hg, Pb, Na, K) in mussel samples from different spanish markets are used to interpret a data base and identify differences between species and origin of the samples. Principal Component Analysis and Potential curves are applied to properly classify unknown samples from representative mussels samples (Mytilus edulis and Perna canaliculus). Also, Principal Components Analysis is used as display method to visualize the relation between the variables and objects of interest.     

Variation of toxaphene indicator compounds in fish from single fishing grounds: conclusions for sampling

The levels of three toxaphene indicator compounds were determined in individual lots of herring, redfish, Greenland halibut and farmed salmon. Concentration levels of the three marine fish species were characterised by a right-skewed frequency distribution whereas residue concentrations in farmed salmon were normally distributed. The toxaphene concentrations in the edible part of redfish, herring and Greenland halibut were found to be positively correlated to the sizes and thus to age. As results show, for representative sampling of a landed catch, not more than 10 individual fishes from typical size classes of a lot are necessary for a pooled sample.     

Spatial differences of chemical features of atmospheric deposition between rainy season and winter in the areas facing to the Japan Sea, Japan

Atmospheric deposition was collected using filtrating bulk samplers at 32 sites in the areas facing to the Japan Sea (AFJS) from April 1991 to March 1994. The data were analyzed for winter (January and February) and the rainy season (June and July) when the climate is just the opposite. The AFJS was geographically divided into five areas, that is western Tohoku (WT), Hokuriku (HR), eastern San-in (ES), western San-in (WS) and northern Kyushu (NK). WT, HR and ES receive more precipitation than other regions in winter. H+ depositions increase in winter except NK. This is mainly due to high winter H+ concentrations. In spite of large amounts of precipitation in WT, HR and ES in winter, nss-SO4(2-) concentration was nearly equal to the average throughout Japan. Namely, nss-SO4(2-) depositions in these areas were nearly twice the national mean. In WT, HR and ES, nss-Ca2+ concentrations in winter are lower than the average of the whole country (less than the half). This may be the cause of the lower potentials of neutralization and the higher remaining acid concentrations in WT, HR and ES than NK and WS.     

Targeting the vulnerable: a review of the necessity and feasibility of targeting vulnerable households

This article examines whether it is possible to target vulnerable households within a geographically defined area. It looks first at the justification for targeting and then reviews recent practical experience in actually trying to reach vulnerable groups. As complex emergencies increasingly last longer, strategies to target vulnerable households are common in the protracted phase of the emergency. While this is often necessary because of a decline in resources, it is not always justified by an improvement in nutritional status or food security of the beneficiary population. Common target groups are the poor and the malnourished, but in complex emergencies these are not always the most vulnerable. Moreover, recent practical experience has shown considerable difficulties in targeting the poor. Methods to target the poor rely on community-based relief committees, whose priorities are not necessarily the same as those of external agencies. This paper gives examples of such targeted assistance programmes in Kenya, south Sudan and Tanzania. The paper concludes that situations where targeting vulnerable households is justified and feasible are extremely limited. It is suggested that if targeting has to be done because of scarce resources, this should be done on a geographical basis and on the basis of nutritional status. Case-study material shows that it is essential to understand the political determinants of vulnerability and to design methods that will reach the most vulnerable.     

南非芬什金伯利岩中产出的两个含金刚石的橄榄岩捕虏体

<正> 尽管金刚石有重大的经济意义,并且每年回收大量金刚石,但其天然形成过程仍有争论。虽然假定大多数金刚石是岩浆成因的,并且与金伯利岩事件有联系,但是金伯利岩中某些捕虏体内金刚石的存在表明,至少有些金刚石是捕获晶。这种非同源成因的金刚石的比例是目前争论问题之一。     

Tennessee's Novice Driver Safety Project: a program to increase parental involvement

Graduated licensing has been implemented in many U.S. states to reduce teenage driver crash involvement. The goal is to introduce teenagers gradually to driving before allowing full, unrestricted licensure. Tennessee, one of the states that introduced graduated licensing, implemented a program to influence both driving by teenagers during the learner stage and restrictions imposed by parents after licensure. In addition to a standard welcome letter, booklets and reminder cards were mailed to parents of teenagers who had just obtained their learner's permits. The booklets and cards were designed to assist parents in becoming more actively involved in their children's driving experiences. The effects of three different approaches (welcome letter only, letter plus booklet, and letter plus booklet plus reminder cards) on parental involvement, teenage crashes, and teenage citations were assessed based on telephone interviews with parents. Although the parents said the booklets and reminder cards were helpful and should continue to be sent to other parents, there were no discernible effects on teenage practice driving and reported parental involvement during the learner stage. Nor was there any measurable influence on restrictions imposed by parents after licensure. It is unknown whether the standard welcome letter affected parental involvement, but overall supervised driving exceeded the state requirements by a substantial margin.