A Review and Analysis of Study Endpoints Relevant to the Assessment of “Long Term” Pesticide Toxicity in Avian and Mammalian Wildlife

Abstract

The ecological assessment of long term or reproductive effects from pesticide exposure in birds and mammals is currently seen to be problematic. In birds especially, the current test results are difficult to extrapolate to a field situation. For example, whereas a majority of laboratory studies report clutch size reductions in response to graded pesticide doses, this effect is rarely, if ever, seen in the wild in response to exposure to toxicants. Also, current laboratory tests in birds provide a very truncated measure of reproductive performance. At the opposite end of the spectrum, the ecological assessment of long-term impacts to wild mammal populations suffers from an overabundance of very detailed information generated on a few rodent and non-rodent test species. It becomes critical here to identify which of the multitude of assessment endpoints should form the basis of an ecological assessment. Whether bird or mammal, I suggest that it is essential to separate parental from developmental endpoints and to apply the different effect levels to agent-based models of population growth and performance. Only then can we hope to gain a real understanding of the true long-term consequences of pesticide or other chemical exposure.

Risk Assessment for Birds and Mammals ‐ Revision of Guidance Document under Council Directive 91/414/EEC (SANCO/4145/2000 – final of 25 September 2002) ‐ Scientific Opinion of the Panel on Plant protection products and their Residues (PPR) on the Science behind the Guidance Document on Risk Assessment for birds and mammals

“…• The current approach does not clearly state what is meant by long-term risk; this issue is considered in detail by Mineau (2005) who states that 'three issues are really rolled into one in the current EU concept of "long-term risk" of pesticides'. Presented below is a brief explanation of the three concepts: o Non-specific effects resulting from long-term or chronic exposure to pesticides -This is where there is long-term exposure which may be the result of a pesticide accumulating in tissues, a pesticide degrading slowly in the environment or when repeated applications are made.…”

“…In a sample of 49 recent studies with mallard ducks, Mineau (2005) found that, 4 % of studies had a NOEC related to eggshell thickness but no evidence of increased breakage. Indeed, population effects in the wild tend to come about after thinning of 18 % or more (Blus, 2003).…”

“…The following overviews are based on Mineau (2005). If the substance being assessed is an endocrine-disrupting substance 25 , section 5.3 should be consulted.…”

“…The number of eggs laid per hen was a measurement that was found to have the lowest NOAEL in a sample of studies analysed for the York workshop (see Mineau (2005) for further consideration of this issue).…”

An Overview of the Persistent Organic Pollutants in the Freshwater System

“…Pesticides are vital for crop protection and human health in many parts of the world [19,20], yet due to their detrimental effects on natural ecosystems [21][22][23], we are becoming increasingly worried about their short and long term harms on the environment. A number of pesticides are in use throughout the world, but the four most important groups are insecticides, rodenticides, herbicides and fungicideseach group contains a rapidly accumulating list of persistent organic compounds capable of contaminating fresh water.…”