United States Environmental Protection Agency

About: United States Environmental Protection Agency is a government organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Population & Environmental exposure. The organization has 13873 authors who have published 26902 publications receiving 1191729 citations. The organization is also known as: EPA & Environmental Protection Agency.

Waterborne outbreaks reported in the United States

Abstract: Epidemic waterborne risks are discussed in this paper. Although the true incidence of waterborne illness is not reflected in the currently reported outbreak statistics, outbreak surveillance has provided information about the important waterborne pathogens, relative degrees of risk associated with water sources and treatment processes, and adequacy of regulations. Pathogens and water system deficiencies that are identified in outbreaks may also be important causes of endemic waterborne illness. In recent years, investigators have identified a large number of pathogens responsible for outbreaks, and research has focused on their sources, resistance to water disinfection, and removal from drinking water. Outbreaks in surface water systems have decreased in the recent decade, most likely due to recent regulations and improved treatment efficacy. Of increased importance, however, are outbreaks caused by the microbial contamination of water distribution systems. In order to better estimate waterborne risks in the United States, additional information is needed about the contribution of distribution system contaminants to endemic waterborne risks and undetected waterborne outbreaks, especially those associated with distribution system contaminants.

The power of expert opinion in ecological models using Bayesian methods: impact of grazing on birds

Abstract: One of our greatest challenges as researchers is predicting impacts of land use on biota, and predicting the impact of livestock grazing on birds is no exception. Insufficient data and poor survey design often yield results that are not statistically sig- nificant or that are difficult to interpret because researchers cannot disentangle the effects of grazing from other disturbances. This has resulted in few publications on the impact of grazing on birds alone. Ecologists with extensive experience in bird ecology in grazed landscapes could inform an analysis when time and monetary constraints limit the amount of data that can be collected. Using responses from 20 well-recognized ecologists throughout Australia, we captured this expert knowledge and incorporated it into a statistical model using Bayesian methods. Although relatively new to ecology, Bayesian methods allow straightforward probability statements to be made about specific models or scenarios and the integration of different types of information, including scientific judgment, while formally accom- modating and incorporating the uncertainty in the information provided. Data on bird density were collected across three broad levels of grazing (no/low, mod- erate, and high) typical of subtropical Australia. These field data were used in conjunction with expert data to produce estimates of species persistence under grazing. The addition of expert data through priors in our model strengthened results under at least one grazing level for all but one bird species examined. When experts were in agreement credible intervals were tightened substantially, whereas, when experts were in disagreement, results were similar to those evaluated in the absence of expert information. In fields where there is extensive expert knowledge, yet little published data, the use of expert information as priors for ecological models is a cost-effective way of making more confident predictions about the effect of management on biodiversity.