Pesticide risk

Problems that rank relatively high in duee of the four typos, or at least medium in all four, include criteria air pollutiuits, stratospheric ozone depletion, pesticide residues on food, and other pesticide risks (runoff and air deposition of pesticides)... 

Thompson, H.M. and Mans, C. (2007). The relevance of sublethal effects in honey bee testing for pesticide risk assessment. Pest Management Science 63, 1058-1061. 

There is a growing need to better characterize the health risk related to occupational and environmental exposure to pesticides. Risk characterization is a basic step in the assessment and management of the health risks related to chemicals (Tordoir and Maroni, 1994). Evaluation of exposure, which may be performed through environmental and biological monitoring, is a fundamental component of risk assessment. Biomarkers are useful tools that may be used in risk assessment to confirm exposure or to quantify it by estimating the internal dose. Besides their use in risk assessment, biomarkers also represent a fundamental tool to improve the effectiveness of medical and epidemiological surveillance. 

Balderacchi M, Trevisan M (2010) Comments on pesticide risk assessment by the revision of Directive EU 91/414. Environ Sci Pollut Res 17(3) 523-528... 

In considering pesticide residues, it was clearly shown that crops from organic production systems contain no or significantly lower levels of pesticide residues than crops from conventional systems (Baker et al., 2002). However, while some scientists are concerned about the potential health impacts from such residues (Porter et al., 1999 Benbrook, 2002), pesticide legislators maintain that current pesticide risk assessments and pesticide registration procedures are adequate and that residues below the current legal limits can not have a negative health impact in humans (e.g. PSD, 2006). 

In Tables 14.9 and 14.10, the last column reports the environmental impact points (EIPs) for typical applications of organic and conventional pesticides derived from the Pesticide Environmental Assessment System, or PEAS. This model produces relative rankings of risks based on defined use rates and use patterns (the formulation used to apply a pesticide, timing, target of the application, spray equipment used, etc). PEAS scores reflect an equal balancing of acute pesticide risks to farm workers, chronic risks via dietary exposure and exposures to birds, Daphnia and bees. 

EPA released the first case study of cumulative risks from 24 OPs in food for scientific review in mid-2000. Public comments were solicited and several scientific panel (SAP) meetings were held on various aspects of EPA s quantitative methods. In December 2001 a preliminary OP-CRA (cumulative risk assessment) was released, this time encompassing 30 OPs, additional foods, more residue data and all major routes of exposure. Public comments were solicited again and another series of SAP meetings were held. The revised final OP-CRA was issued in June 2002 after more than 20 SAP meetings and four rounds of public comment (US Environmental Protection Agency, 2002). It is the most sophisticated and data-rich pesticide risk assessment ever carried out. 

How can we best approach this task In the last decade, significant public and private resources have been invested with the goal of reducing pesticide risks through ... 

Regulation, and the FQPA in particular, has advanced knowledge of pesticide risks and addressed residential risks reasonably well, but has done little to reduce pesticide dietary risks. The FQPA is fundamentally sound law, but it has not delivered fully on its promise to reduce children s pesticide risks because of the EPA s hesitancy to fully use the law s strong new provisions. 

EFSA (2008) Conclusion regarding the peer review of the pesticide risk assessment of the active substance etofenprox. EFSA Scientific Report 213. European Food Safety Authority, Parma, pp 1-131 http //www.efsa.europa.eu/en/scdocs/scdoc/213r.htm... 

Winter CK. 1992. Dietary pesticide risk assessment. Rev Environ Contam Toxicol 127 23-67... 

The techniques used to establish the risks posed by pesticides are dynamic and evolving. The passage of the FQPA in 1996 paved the way for the development of sophisticated computational models for assessing pesticide exposure, and future refinement of such models is anticipated. Such advancements in pesticide risk assessment techniques should be applicable to the risk assessment of other chemicals in foods and in the environment. 

Harmonize the data and methods used to test and assess pesticide risks, so as to help governments work together and improve the quality of the data and the rigor of the... 

In addition to considering the FQPA-relevant areas of uncertainty, assessments of pesticide risk to children also consider applying part or all of the FQPA factors in certain situations to account for... 

Variability and uncertainty affect every element of every risk assessment. For example, participants in the European Workshop on Probabilistic Risk Assessment for the Environmental Impacts of Plant Protection Products (EUPR A) were asked to list sources of uncertainty affecting current procedures for assessing pesticide risks to aquatic... 

FIGURE 1.2 Examples of differing degrees of conservatism in assumptions used in pesticide risk assessments. 

The Pellston workshop in February 2002, which produced this book, aimed to develop guidance and increased consensus on the use of uncertainty analysis methods in ecological risk assessment. The workshop focused on pesticides, and used case studies on pesticides, because of the urgent need created by the rapid move to using probabilistic methods in pesticide risk assessment. However, it was anticipated that the conclusions would also be highly relevant to other stressors, especially other contaminants. 

Ames B, Gold L. 1989. Pesticides, risk, and applesauce. Science, Letters 244 755-757. 

For pesticide risk assessments, it may often be necessary to assess impacts of the same pesticide used in different crops, in different seasons, in different geographic regions, and on different species and ecosystems. This will require the use of multiple scenarios and possibly multiple assessment endpoints. 

From the standpoint of practical regulatory assessment, it would be desirable to reach a consensus on the selection of methods for routine use for pesticide risk assessments while recognizing that there may be scientific reasons for preferring alternative methods in particnlar cases. Such a consensus does not yet exist. Further case studies are required, covering a range of contrasting pesticides and scenarios, to evaluate the available methods more fully. While a consensus is lacking, it is important that reports on probabilistic assessments clearly explain how their methods work and why they were selected. 

The workshop recognized the importance of dealing with model uncertainty but did not evaluate the alternative approaches in detail. Further work is required to identify instances of model nncertainty for pesticide risk assessment and to develop guidance on how to deal with it. Some possible approaches are briefly discussed below. 

An approach that is sometimes helpful, particularly for recent pesticide risk assessments, is to use the parameter values that result in best fit (in the sense of LS), comparing the fitted cdf to the cdf of the empirical distribution. In some cases, such as when fitting a log-normal distribution, formulae from linear regression can be used after transformations are applied to linearize the cdf. In other cases, the residual SS is minimized using numerical optimization, i.e., one uses nonlinear regression. This approach seems reasonable for point estimation. However, the statistical assumptions that would often be invoked to justify LS regression will not be met in this application. Therefore the use of any additional regression results (beyond the point estimates) is questionable. If there is a need to provide standard errors or confidence intervals for the estimates, bootstrap procedures are recommended. 

In conclusion, we believe that error propagation methods like Monte Carlo, Bayesian Monte Carlo, and Ist-order error analysis should be promoted and extensively used in pesticide risk assessments implemented in both the United States and Europe. 

Most of the rest of this chapter is devoted to reviewing how bounding methods can address the following challenges routinely faced by analysts in pesticide risk... 

In some cases, the workshop produced a near consensus on how to resolve the issue, but further work is required to conhrm and implement the conclusion. In most cases, however, the workshop has identihed a range of possible solutions and further work is required to evaluate them. Uncertainty analysis in pesticide risk assessment is highly encouraged however, uncertainty analysis should be used and interpreted with caution. The methods used should be justified and described in detail in every assessment. 

The workshop did not reach firm conclusions on which methods of uncertainty analysis are suitable for use in pesticide risk assessment, or when they should be used. 

The authors argue, though, that the EPA s notion of risk is fatally flawed because it assumes that the risk is zero if the pesticide is banned rather than the difference between the pesticide risk and whatever replaces the pesticide. 

Gallivan, G.J., Surgeoner, G.A. and Kovach, J. (2001) Pesticide risk reduction on crops in the Province of Ontario. J Environ Quad, 30, 798-813. 

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