Choice for the Protection of Health and the Environment: The CACCIA - PowerPoint PPT Presentation

Critique of “Pesticides: Making the Right Choice for the Protection of Health and the Environment”: The CACCIA Report Presented by: Earle R. Nestmann, Ph.D. Vice President CANTOX HEALTH SCIENCES INTERNATIONAL

Caccia Standing Committee Report Stated Objective of Committee Report: “…a study on the management and use of pesticides in Canada including an evaluation of the performance of the Pest Management Regulatory Agency in preventing pollution and in protecting the environment and human health.” Reasonable Expectations:  Reflect the current status of pesticide use in Canada  Concentrate on potential risks of current pest control products

Reality (Hidden Agenda):  Fear mongering, by lack of objectivity and by clear bias against pest control products  Focus on exaggerated effects of discontinued pesticides, e.g. , the organochlorines  Definite health benefits from pesticide use largely ignored  Comparisons of pesticides with tobacco, pollutants, lead and asbestos – No health benefit from tobacco and pollutants – Lead and asbestos are single entities not groups of diverse chemicals  The Committee report contains numerous shortcomings, including unsupported generalizations and misleading information.

Example: Generalization  “ The scientific research that describes the impact of pesticides on wildlife suggests that pesticides affect reproduction, growth, neurological development, behaviour and the functioning of the immune and endocrine systems.” (Section 5.1)  Perfect example of the widespread generalizations littering the Committee report: “impact of pesticides” ; “pesticides affect” .  Such a statement, in the absence of any kind of exposure information, is totally useless for assessing health risk.  All chemicals, even oxygen and water, are capable of adverse effects if administered in high enough doses.

Example: Product Not Used in Canada  “Dr. Mineau told the Committee that a single granule of carbofuran can be instantly lethal to a small bird.” (Section 5.2)  The granular form of carbofuran is no longer registered for use in Canada.  Nowhere is the size of the granule described, leaving the impression that it might be as small as a grain of salt, which is not the case.

Example: Suggestive Use of Epidemiology  “It’s not like leukemia and lymphoma, for which we have reasonably good evidence to act on.” (Section 5.3)  Probable that the witness quoted was referring to the hypothetical association between 2,4-dichlorophenoxyacetic acid (2,4-D) and non- Hodgkin’s lymphoma.  The huge toxicology database for 2,4-D demonstrates that it is not a carcinogen in animals.  Epidemiology studies show it unlikely to be responsible for the production of non- Hodgkin’s lymphoma or other tumours in man (i.e., farmers have lower incidences than general population).

Example: Scare Tactics  “Breast cancer is the other big concern with pesticides” (Section 5.3)  Such a categorical statement is not supported by scientific evidence.  The pesticides primarily implicated, including DDT (or its principal metabolite DDE) and dieldrin, aldrin, and chlordane have been discontinued from use in Canada.  Results from reports of possible associations are very inconsistent (i.e., some positive associations, others no association, and in some studies lower breast cancer incidence).  Evidence from animal studies shows reduction of breast and related cancers.

 “Women, whose bodies contain greater proportions of fatty tissue, are more likely to accumulate persistent organic pollutants (POPs). Some researchers assume on the basis of this fact that women exposed to pesticides may run a higher risk of developing breast cancer.” (Section 7.2)  Continuing focus on persistent chlorinated pesticides that are no longer registered for use, and for which environmental levels are decreasing.  Life expectancy for women increased from 66 years of age in 1940- 42 to 76 years in 1970-72, the period during which there was widespread use of organochlorinated pesticides in Canada.  Despite persistent residues of organochlorinated pesticides, life expectancy for women has increased further to 81 years of age in 1990-92.  Based on the studies with fish-eating birds (cormorants), there is no doubt that peak environmental levels of these persistent organic pollutants, in Canada, are in the past.

Example: Misleading Information  “Wind and water bring them to Canada, where they have been found in human breast milk”. (Section 5.4)  “...women accumulate contaminants in their bodies and excrete them in breast milk thus subsequently passing them on to the newborn. The most dangerous contaminants for the child are those which affect brain development because of the brain’s rapid growth at this stage.” (Section 6.5)  The benefits of breast feeding far outweigh the hypothetical risks.  Although low levels of organochlorine pesticides, particularly DDT have been detected in breast milk, babies are not at increased risk.  Levels of DDT also have declined significantly in countries that have restricted its use.  Environmental terrorism discourages breast feeding and proper infant nutrition.

Example: Misinformation  “Well known organophosphates: chlorpyrifos, diazinon, glyphosate, and malathion.” (Section 5.6)  Glyphosate is not an organophosphorus insecticide (or “organophosphate”).  Biochemical characteristics and mode of action of glyphosate are unrelated to the listed organophosphorus insecticides.  Inclusion of glyphosate in this group casts further doubt on the competence of the Committee for evaluating the PMRA or any pesticide issues.

Example: Scare Tactics  “In terms of impact on human health, it is believed that organophosphate compounds inhibit the enzymes that are essential for the proper functioning of the central nervous systems, causing dizziness and sometimes convulsions that may lead to death.” (Section 5.6)  It is obvious that such effects would result only from high exposures, such as accidental poisoning or attempted suicide.  “The Committee learned that there are gaps even in studies on mammals; for example, little is known about the effect of phenoxy herbicides on mammals or the long-term effects of synthetic pyrethroids. These gaps suggest that there may be other gaps in our knowledge of the effects of other chemical groups of pesticides as well.” (Section 5.9)  2,4-D, a phenoxy herbicide, is one of the best studied agricultural chemicals with a database of literally hundreds of toxicology studies, pointing out that these statements are not only misleading but blatantly false.

Example: Scare Tactics (cont.)  “In addition, their diets are appreciably different from those of adults (consisting largely of fruits, vegetables and mother’s milk), and the younger they are, the more limited their ability to metabolize and eliminate residual toxic substances.” (Section 6.3)  Consumer Reports (March, 1999) cited as the source for this excerpt, was critiqued by the Society of Toxicology (SOT) Council, the largest professional organization of toxicologists worldwide.  Methodology was not consistent with standard principles and practices in toxicology and risk assessment (SOT, 1999). – “Negligible risks need to be put in proper perspective so that consumers are not unnecessarily alarmed.” – “Unsubstantiated claims of exaggerated risk may have the unintended effect of diverting consumers from healthy behaviours, e.g. , consumption of fruits and vegetables.” – “Additionally, too many false alarms may create a dangerous apathy with the possible result that significant environmental risks may be ignored.”

Example: Scare Tactics (cont.)  “People who suffer from asthma or allergies, people with multiple chemical sensitivity (MCS) and older people make up a second vulnerable group” (Section 7.3).  Based on current peer-reviewed literature, the main risk factors in the development of asthma and allergy include: genetic predisposition; environmental tobacco smoke; house dust mites; and, cockroach allergen.  There is insufficient evidence for the association of chemical sensitization and the development of asthma.  As of yet, it has not been determined if the basis of MCS is partly physical or mostly psychological.

Example: Poor Science  “With regard to neurological effects...we see kids all the time who after using it either as an insect repellent or for head lice will have seizures and prolonged confusion. This happens all the time. We think that’s just an acute effect...Over the long term what does that do? If you can have that effect from putting insect repellent on your infant’s head, what happens to your neurological system after 15 years of exposure?” (Section 6.8)  There is confusion with respect to modes of action of repellents and of head lice treatments.  The concurrent use of the statements “after using it either as an insect repellent or for head lice” and “what happens to your neurological system after 15 years of exposure” gives the impression of regular, frequent, and prolonged exposure, which is unlikely based on the uses indicated.