ARSENIC CONSUMPTION AND HEALTH RISK PERCEPTIONS IN A RURAL WESTERN U.S. AREA1

ABSTRACT: Churchill County, Nevada, has approximately 23,000 residents, among whom an estimated 13,500 relied on private wells for water supply in 2002. This study examined exposure to arsenic in water supplies among residents with private domestic wells and factors related to householder choice to consume tap water. It compared opinions and concerns about water quality with consumption habits and observed concentrations from tap water samples. The results from 351 households indicated that a majority (75 percent) of respondents consumed tap water and that a minority (38 percent) applied treatment. Approximately 66 percent of those who consumed tap water were exposed to concentrations of arsenic that exceeded 10 ppb. Water consumption was related to application of treatment. Among 98 respondents who were not at all concerned about the health effects of aqueous arsenic, 59 (60 percent) reported consuming tap water with concentrations of arsenic exceeding 10 ppb. Conversely, among 86 respondents who were highly concerned about arsenic, 33 (37 percent) consumed tap water with concentrations of arsenic exceeding 10 ppb. Results from a national sampling effort showed that 620 of 5,304 private wells sampled (11.7 percent) had arsenic concentrations above 10 ppb. The paradox of awareness of arsenic in water supplies coupled with consumption of aqueous arsenic in concentrations greater than 10 ppb may be common in other parts of the nation. Enhanced educational efforts, especially related to tap water sampling and explanations of efficacy of available treatment, may be useful means of reducing exposure through private water supplies.     

Acute toxic hazard evaluations of glyphosate herbicide on terrestrial vertebrates of the oregon coast range

GOAL, SCOPE AND BACKGROUND: The degree to which dose responses of model organisms (lab rodents) can adequately predict dose responses of free-ranging wild mammals or amphibians is unknown, and the relative sensitivity of such species to body loading of a toxicant such as glyphosate is seldom reported. For relative effects of dosage, we compare sensitivity of nine wild vertebrate species to effects of high doses of glyphosate in Swiss-Webster laboratory mice both by gavage and by intraperitoneal injection. We also evaluate sublethal effects of herbicide exposure on behavior and reproductive success of one mammal and one amphibian species. METHODS: Comparisons of acute toxicity of glyphosate were made with intraperitoneal dosings of technical glyphosate isopropylamine salt to nine species of terrestrial vertebrates (five amphibians, four mammals) and compared with responses in Swiss-Webster laboratory mice. Animals collected from sites that had no recent herbicide application were allowed 7-14 days to equilibrate in captivity before treatment. RESULTS: Median lethal dose ranged from 800 to 1,340 mg kg(-1) in mammals, and 1,170 to >2,000 mg kg(-1) in amphibians, with Oregon vole being the most sensitive. White lab mice were in the middle of the mammalian range. Tailed frog, at >2,000 mg kg(-1) was the least sensitive. Calibration of IP sensitivity to oral administration by gavage indicated that roughly four times as much glyphosate must be administered to obtain a comparable estimate of lethality. Administration by gavage in highly concentrated solutions tended to cause physical injury, hence may prove less useful as a relative indicator of toxicity. When sublethal dosages were given to roughskin newts or chipmunks, mobility and use of cover appeared largely unaffected. DISCUSSION: Direct toxic effects of spraying glyphosate under normal forest management seem unlikely for the nine species examined. Nor could we detect significant indirect effects of exposure on behavior and use of cover features in two species. There may be effects on other aspects of the field biology of these animals, such as reproductive rates, which we did not investigate. Recent field data indicate that changes in habitat quality following herbicide application can result in high reproductive activity in species associated with the grasses and forbs that proliferate following field applications. CONCLUSIONS: When compared to field data on body burdens of wild mammals exposed after aerial application of glyphosate at maximum rates in forests, there seems to be a large margin of safety between dosages encountered and those causing either death or limitation of movement, foraging or shelter. RECOMMENDATIONS AND PERSPECTIVES: Margins of safety for small mammals and amphibians appear to be large under any probable exposure scenarios, however our results indicate high variability in responses among species. Uncertainty introduced into field studies from unknown sources of mortality (e.g, likely predation) must be considered when interpreting our results.     

Food aid and food crisis in Sub-Saharan Africa: Statistical trends and implications*

This paper documents the rapid expansion and changes in food aid flows to Sub-Saharan Africa up to mid-1985. Trends for Sub-Saharan Africa as a whole and for the more seriously affected countries are examined, as are the comparative experiences of food aid of individual countries in the region. Table 11 lists the Sub-Saharan African countries and indicates the most seriously affected food-short countries, as defined by the WFP/FAO task force. It should be borne in mind that some practical problems exist in compiling data on food aid. These include lack of availability of reliable data, especially of most recent data; lack of common terminology and definitions; and different accounting systems. These data problems are sometimes a source of confusion. However, the basic facts are clear: food aid gradually emerged during the early 1980s as a resource too often of considerable significance to many countries of Sub-Saharan Africa. These trends were only accelerated with the crisis of 1984-1985. These facts provide a point of reference for further analysis of the sources of the crisis, its actual dimensions and consequences.     

Prenatal exclusion of Hurler's disease by leucocyte α-L-iduronidase assay

Hurler's disease was excluded in a fetus at 23 weeks' gestation by demonstrating normal iduronidase activity in fetal leucocytes following failure of amniotic cell culture after amnic-centesis at 16 and 19 weeks' gestation. The diagnosis was confirmed in the neonate.     

Achieving quality environmental audits: Twenty tips for success

In 1995 the authors spent a considerable amount of time conducting audits and audit training classes all over the world. In rolling out Colgate-Palmolive's reengineered environmental audit program, they coupled a two-day training program with a three-day audit. Whether in Asia-Pacific, South America, Europe, or the United States, auditors, especially those newly trained, always seemed to fall into the same traps time and again. In order to facilitate the learning process, the authors prepared a list of 20 tips to use at the beginning and end of all training programs and audits. In this article, the authors share the 20 “golden rules” to help all auditors improve the quality of their audits.     

Thermal and mechanical properties of poly(lactic Acid) and poly(ethylene/butylene Succinate) blends

In this study, blends of poly (lactic acid) (PLA) with poly(ethylene/butylene succinate) (Bionolle) have been investigated for their thermal and mechanical properties as a function of the concentration of Bionolle. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and tensile tests were used to characterize the blends. From the results of the DMA and DSC, it was found that this blend system was not miscible within the compositions studied. DSC results showed that adding Bionolle aids in crystallization of PLA. It was observed that increasing the Bionolle concentration led to a slight increase in the strain-at-break of the blends but a decrease in the Young’s modulus and ultimate tensile strength. Biaxially oriented films showed an increase in tensile strength, modulus, and strain-at-break.     

Patterns,correlates, and paternity consequences of extraterritorial foray behavior in the field sparrow (Spizella pusilla): an automated telemetry approach

Behavioral Ecology and Sociobiology - ᅟMales of fiddler crabs (genus: Uca) construct courtship structures using mud or sand to attract mate-searching females for underground mating. A sensory...     

Circumpolar status of Arctic ptarmigan: Population dynamics and trends

Rock ptarmigan (Lagopus muta) and willow ptarmigan (L. lagopus) are Arctic birds with a circumpolar distribution but there is limited knowledge about their status and trends across their circumpolar distribution. Here, we compiled information from 90 ptarmigan study sites from 7 Arctic countries, where almost half of the sites are still monitored. Rock ptarmigan showed an overall negative trend on Iceland and Greenland, while Svalbard and Newfoundland had positive trends, and no significant trends in Alaska. For willow ptarmigan, there was a negative trend in mid-Sweden and eastern Russia, while northern Fennoscandia, North America and Newfoundland had no significant trends. Both species displayed some periods with population cycles (short 3–6 years and long 9–12 years), but cyclicity changed through time for both species. We propose that simple, cost-efficient systematic surveys that capture the main feature of ptarmigan population dynamics can form the basis for citizen science efforts in order to fill knowledge gaps for the many regions that lack systematic ptarmigan monitoring programs.