Quality assurance (San Diego, Calif.)最新文献

Measuring is an essential component of any Total Quality Management System. In the Good Laboratory Practices arena this normally is done by measuring the quality of the customer's (e.g. Toxicology) output. This paper describes a holistic approach to measuring the effectiveness of the Quality Assurance Unit (QAU), which includes measures of both the customer and the QAU. When taken together, these measures provide management with a picture of the effectiveness of the QAU.

Enacted into law by Congress in August 1996, the Food Quality Protection Act (FQPA) is the most significant piece of federal pesticide legislation since the 1988 amendments to the Federal Insecticide, Fungicide and Rodenticide Act. FQPA was hastily drafted and approved towards the end of the 1996 Congressional session. The new law was advertised as resolving some long-standing problems; however, it is clear now that it has also created some new ones. Since the FQPA's passage, the U.S. Environmental Protection Agency has issued numerous rules and regulations that are being used to evaluate and judge the safety of pesticide use on foods. This article discusses some of the major provisions of the new law and their impact to the U.S. pesticide industry.

The calibration of balances is routinely performed both in the laboratory and the field. This process is required to accurately determine the weight of an object or chemical. The frequency of calibration and verification of balances is mandated by their use and location. Tolerance limits for balances could not be located in any standard procedure manuals. A survey was conducted to address the issues of calibration and verification frequency and to discuss the significance of defining tolerance limits for balances. Finally, for the benefit of laboratories unfamiliar with such procedures, we provide a working model based on our laboratory, the Upper Mississippi Science Center (UMSC), in La Crosse, Wisconsin.

Environmental measurements often produce values below the method detection limit (MDL). Because low or zero values may be used in determining compliance with regulatory limits, in determining emission factors (typical concentrations emitted by a given type of source), or in modeling efforts, there is considerable interest in methods for determining detection limits and in procedures for using MDLs in summary statistics. Selection of methods for determining detection limits and treatment of MDL data should depend on the end-use of the data. The MDL should be determined in the environmental matrix that contains the analyte of interest. Treatment of missing values (values below the MDL) should be specified before the initiation of a measurement effort. When calculating a mean value for a source or area, one approach is to set the missing values at the MDL. This approach is appropriate when there are significant risks associated with incorrectly assuming a low level of a toxic compound; this method of summarizing data introduces a positive bias. Missing values may be assumed to equal zero if there is not a high risk of overlooking a hazard; this method produces a negative bias. However, if enough measurement data are available and the distribution of these data can be established then look-up tables can be used to estimate missing values, using statistically based estimates, without introducing high or low biases in a calculated mean.

The Bílovka River is one of the most extensively drained rivers in the Odra catchment. The problem of the naturalization of the downstream part of the river is complicated by enormous pollution of surface water. The investment into the catchment requires a complex approach to provide successful ecological conditions in the reclaimed part of the river. The treatment must resolve the problems, not just reduce their influences. An ecological study of such a treatment must consider ecotoxicological effects as well. The results of an ecotoxicological evaluation of the catchment are demonstrated and discussed. These results contribute to the final goal of the ecological study: to prepare conditions for regeneration of the catchment in terms of primary needs for stable ecological conditions near the mouth of the river.

There is a need for OHS management systems that can be integrated with systems for the management of other organizational priorities including quality, environment, productivity, and the like. The present article presents an overview of the draft Australian/New Zealand Standard on Occupational Health and Safety Management Systems as a step toward the development of such integrated systems. This draft standard presents a five-stage process of OHS management. The five stages--commitment and policy, planning, implementation, measurement and evaluation, and management review and improvement--will create a cycle of activity that can lead to the continual improvement of processes and systems for OHS management in the workplace.

Restoring and safeguarding ecosystem health is a major challenge for the 21st century. Man-made substances, particularly persistent bioaccumulative substances have been among the forces that have contributed to weakening the health of ecosystems. However there are other stresses that interact synergistically with chemical stress. These forces, such physical restructuring (habitat change) tend to enhance the impacts of chemical stresses. A dose-response framework that encompasses an array of stresses with synergistic and occasional antagonistic effects is proposed for the assessment of ecosystem health. The flow of ecosystem services is curtailed in damaged systems. These services, such as provision of biodiversity, potable water, foodstuffs, sequestering of contaminants, will determine the suitability of ecosystems for humans. Linking ecotoxicology to ecosystem health provides an avenue for relating a variety of pressures on ecosystems to the conditions essential to sustain life that includes human communities.

The assessment of the environmental impact of pollutants at the ecosystem level raises theoretical and methodological problems of substantial magnitude. Despite the usefulness of a more reductionist approach related to the measure of the effects of pollutant on populations, such as specific toxicity testing or--regarding the assessment of impact of chronic exposure--the use of various biomarkers, these measures do not provide data relevant to conclusions at the community and ecosystem level. The assessment of effect on entire ecosystems requires two kinds of information: (1) What are the consequences of pollutant exposure on the community structure, and (2) what is its impact on fundamental ecological processes that control the ecosystem functioning? Disturbances of structure may be appraised in terms of the major parameters that currently describe it at the community level, such as species richness, ecological diversity, and dominance. The assessment of pollutant effect on ecosystem biodiversity, though underestimated for a long time, is a major issue in applied ecotoxicological research. Accurate attention must be given to keystone species, which in both terrestrial and aquatic ecosystems control the diversification of the whole trophic web in a community. Therefore, if induced by a given pollutant, the decline of the populations of a keystone species may lead to a major destructing of the community. The second major issue in ecotoxicological research is assessment of damage to ecosystem functioning. Because productivity is of such practical importance, appraising changes in primary and secondary productivity is acutely needed. Indeed, chronic pollutant exposure is a permanent threat to biological natural resources as it impedes their production and renewal. Another major point in the assessment of effects at the ecosystem level is the effect of pollution on natural biogeochemical cycles, as well as the study of the ways through which a number of various and often common contaminants, some of them acting at global scale, interact with such cycles. It is also fundamental to assess the effects of pollutants on decomposer activity in both soil and natural waters and on its interaction with biogeochemical processes such as element recycling. In a larger context, though still almost unexplored, ecotoxicology is related to assessment of effects on complex ecosystem assemblages on a regional scale (i.e., landscape ecology and its relationship to functional ecotoxicology).