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

Earle R. Nestmann, Ph.D. Vice President CANTOX HEALTH SCIENCES INTERNATIONAL

Critique of “Pesticides: Making the Right Choice for the Protection of Health and the Environment”: The CACCIA Report

Presented by:

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

Caccia Standing Committee Report

 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.

Reality (Hidden Agenda):

 “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: Generalization

“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: Product Not Used in Canada

 “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: Suggestive Use of Epidemiology

 “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.

Example: Scare Tactics

 “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.

 “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: Misleading Information

“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

• rganophosphorus 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: Misinformation

 “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

 “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

• rganization 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: Scare Tactics (cont.)

 “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

• f 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.

Example: Poor Science

 “For example, people with MCS can suffer a wide range of

symptoms including burning eyes, breathing problems, muscular weakness, headaches, fatigue, asthma, allergies and chronic infections.” (Section 7.3)

 The source cited defines environmental hypersensitivity as “an

abnormal response of one’s body to everyday substances including food, chemicals, drugs, air pollution, perfumes, pollens, dust, and molds”.

 Also disclosed on this website was a list of suspected causes that

included: “heredity, viral, bacterial or fungal infections, chemical exposure, stress - positive or negative, and nutritional habits”.

 The lack of any mention of these other triggers in the Committee

report is an example of selective reporting, leading to the erroneous assumption that these ailments, for which a psychological basis is largely responsible, are attributed entirely to pesticides.

Example: Selective Reporting

 “Some researchers have succeeded in demonstrating a

significant dose-response relationship between fields sprayed with herbicides and the risk of contracting non- Hodgkin’s lymphoma, while others have not succeeded in statistically demonstrating this link between the presence of pesticides and the various illnesses observed.” (Section 7.4)

 Objectivity is essential for scientific credibility, and it is very

important to remember that research results validate the truth of a hypothesis, not the reverse.

 The above statement, with reference to the idea of “success”

reflects an obvious bias by presuming that studies reporting no association should be discounted as failures.

Example: Lack of Objectivity

 To ensure credibility it is important that risk be based on a

weight of evidence assessment.

 All epidemiology studies, whether they report positive or

negative associations, are subject to the same inherent limitations including establishing accurate exposure data, the presence of numerous confounding factors (although major factors such as smoking can be controlled for it is impossible to account for all possible confounding factors), and sample size.

 Thus, all data must be considered, including genotoxicity/

mutagenicity, animal toxicology and mechanism of action studies, to discern the possibility of a causal association.

Example: Lack of Objectivity (cont.)

“The Inuit are particularly affected by the accumulation

• f toxaphene, chlordane, and polychlorinated

biphenyls (PCBs) in their bodies.” (Section 7.5)

These pesticides and PCBs have been discontinued

from use in Canada.

As stated previously, detection of trace levels cannot

be interpreted to mean anyone is “particularly affected”.

Furthermore, potential risks of these discontinued

pesticides have little bearing on current, non-persistent pesticides used in lawn care.

Example: Exaggeration

 “...A chemical was accepted for use in Canada; thirteen

farmers were occupationally exposed to it. For how long? It’s a new chemical. We don’t know what it’s going to do to anybody…For four to seven hours they were exposed… That’s four to seven hours and 13 farmers” (Section 7.12)

 Such studies are used to estimate potential exposures

immediately after application, only.

 It is not the intention of this particular type of study to provide

an indication of “what it’s going to do to anybody” over long- term use.

 Furthermore, the PMRA would not rely on such a study as an

indication of potential long-term health effects.

Example: Lack of Understanding (Clueless)

 “After this series of hearings, the Committee is in a position to say

that while the scientific evidence remains incomplete, pesticides do represent a sufficiently disturbing threat to human beings and the environment to justify special attention.” (Section 7.14)

 The Committee report does not come close to providing sufficient

evidence to justify this opinion for pesticides currently in use.

 Furthermore, recent surveys indicate that Canadians are living

longer and are healthier than ever (Statistics Canada, 1999, 2000).

 “We compound our worries beyond all reason. Life expectancy in

the United States has doubled during the twentieth century. We are better able to cure and control diseases than any other civilization in

• history. Yet we hear that phenomenal numbers of us are dreadfully

ill” (“Culture of Fear”, Safe, 2000).

Example: Bad Science

“The risk presented by the use of a pesticide to human

and environmental health is a function of two things, the toxicity of the pesticide and the quantity of the pesticide to which humans and the environment are exposed.” (Section 8.2)

It requires mentioning that, discussion of risks of

health effects presented in the previous sections of the Committee report have for the most part ignored the exposure function of the risk equation.

Example: Misleading

 “When you review the evidence, there’s a huge mishmash. There

are probably 300 studies out there looking at all different outcomes in humans, but it’s difficult to link with pesticides, to try to break it down into what they’ve been exposed to.” (Section 5.3)

 Another good example of a sweeping generalization.  No effort to identify pesticides.  No effort to distinguish between discontinued and currently

registered pesticides.

 Far more that 300 studies investigating possible associations

between pesticide exposures and risks of adverse effects in humans.

 A MEDLINE search for literature containing “pesticides” and

“epidemiology” returned close to 3000 records.

Example: Generalization

One of the reasons given by the Standing Committee

• n Environment and Sustainable Development for

writing this report was “a study into the use of pesticides and their impact on human health and the environment is overdue” (Introduction, page 1).

After evaluating this report from a health perspective, it

can be said that this is not such a study.

Conclusions

 Focus was largely on discontinued pesticides, such as the

• rganochlorines, rather than concentrating on currently

registered pesticides.

 Health effects were generalized and presented as if pesticides

were a single entity rather than many individual chemicals with widely differing chemical, physical, and toxicological characteristics.

 There was limited effort to assess and quantify current

exposures to pesticides.

 The tone of the report reflects a personal bias against pesticide

use rather than an objective evaluation of the current status of pesticide use in Canada.

Why the Document Fails in Its Stated Objectives (But Not Hidden Agenda)