In everyday life we are exposed to a wide variety of chemicals, usually at much lower levels than those working with the chemicals and those exposed to accidental spills. We have been living so close to these chemicals that we tend to ignore them and assume that they are safe and their use presents no risk. These assumptions are not true, and there is increasing evidence to support this statement. Low level chronic exposures are now understood to be more serious than previously thought ^{1 , 2} .

Pesticides are poisons, used to eliminate pests and designed for maximum impact on various target species. They include insecticides, herbicides, fungicides, rodenticides and bacterial disinfectants. A typical pesticide will consist of an active agent such as 2,4-D, and a number of carrier chemicals which are generally portrayed as biologically inert ingredients. The inert ingredients usually make up 95 to 99% of the product and include such substances as carbon tetrachloride and toluene. The Attorney General of the State of New York has noted that "inert" ingredients can contain some of the most dangerous substances known. The most common herbicides used in lawn care in Canada at present are chlorphenoxy compounds which are used to kill broad leaved plants. The major ingredient is 2,4-dichlorphenoxyacetic acid (2,4-D) and during manufacture other substances may be produced which contaminate the product, including dioxins such as tetrachlorodibenzo-p-dioxin (TCDD). 2,4-D was banned in Sweden in 1989. Toxicity to humans and other species results from the ability of 2+13 to decrease oxygen consumption in tissues and disrupt carbohydrate and endocrine metabolism. The second most common herbicide used in domestic situations is glyphosate. This herbicide is an organic acid which can affect the function of the liver, kidney, skin, eyes, and can cause symptoms such as anorexia, vomiting, and muscle weakness. 

Other pesticides, such as the organophosphates, are used in lawn care for the control of insect populations. They act on the nervous system by inhibiting the enzyme cholinesterase. The most widely used agent is chlorpyrifos, but others are diazinon, malathion and parathion. For most of the chemicals there is limited information available on the biological activity of mixtures of the different chemicals.

A pesticide is usually directed at a particular target species (for example dandelions), which is inevitably surrounded by other "desirable" species such as grass. Only a small amount reaches the target and this may vary from as little as 0.00000018% to as much as 5% for some weeds ⁵.

Off target movement due to aerial drift, volatilization and leaching is an important issue and means that people and property will be exposed to pesticides even if they do not want to. When one lawn is sprayed, the neighbours share the chemical, each lawn in a residential area can contaminate at least 30-40 other residences. Up to 80% may be lost by dispersal, and continental movement of pesticides has now been documented.

Once the chemical settles, airborne vapours continue to disperse, and lawn pesticides will continue to be spread to innocent bystanders through run-off and direct contact. For example, a recent study has shown that up to 3% of the pesticide applied to lawns may be tracked into homes on the feet of those walking over a sprayed area. 2,4-D could be detected in carpet dust at significant levels up to one year after the original lawn application. Tracking-in may be the most important aspect of human exposure based on the study of two Arkansas towns where urine samples from children were examined for the presence of 2,4-D. Somewhat surprisingly the herbicide was found to be present in 18% of those living in a town next to a factory that manufactured 2,4-D, while 23% of those living in a town without such a facility were contaminated. Lawn application of pesticides may result in chronic indoor exposure and detectable levels of pesticide in the children that occupy the house.

There are other factors which might increase the susceptibility of the human population to low level chemical exposure. For example stress has been shown to increase the exposure of the brain and central nervous system to certain chemicals. The body's natural defense system, the blood brain barrier, becomes "leaky" ⁹, ^1O. Thus any form of stress may accentuate the potential for toxic effects of low level exposures.

In the February, 1998, issue of Scientific American there are some important statistics about the exposure of children from playing on carpets indoors. The fact that the pesticides are tracked in and deposited on carpets leads to the observation that children are exposed quite innocently to a significant number of cancer producing substances a day - and we suggest that these could be avoided.

The timing of exposure is also important. A developing fetus or child may be particularly susceptible at certain times. There is increasing evidence that the chemicals which mimic the effects of hormones can have major deleterious effects at extremely low levels. Many of the pesticides are known to be hormone mimics including 2,4-D and its contaminants. Intrauterine exposure to pesticides which are hormone mimics may result in impaired motor performance, deficits in memory and learning, reduced ability to concentrate, reduced tolerance to stress, impaired sexual development and aberrant behavior in adult life ⁶.

Most people with chemical sensitivity develop symptoms or experience physiological dysfunction when exposed to the pesticides used on lawns, that is at least 5% and probably 16% of the population. The symptoms of physiological dysfunction that these people experience vary and include the onset of fatigue, muscle pain, muscle weakness, cramping, diarrhea and asthma. Some experience life threatening events such as anaphylaxis or heart rhythm problems. Such effects are very real and incapacitating for those experiencing them and would not be predicted from classical toxicological studies. For many people, living in an average Canadian neighborhood is both stressful, with the constant threat of exposure, and harmful, from the effect of the exposures. Their only choice is to avoid pesticides. In order to escape the harmful effects, some of these people are forced to leave their homes for prolonged periods of time whilst their neighbours, spray their lawns. Unfortunately, these people have no place to go. The extra costs jeopardize their home ownership, and their repeated forced retreats can result in loss of employment. Voluntary notification has not solved the problem for the chemically sensitive. These people live in a constant state of threat and fear, and these factors alone have a very negative health effect.

2. Calabrese EJ 1994 "Biological effects of low level exposure." Lewis Publishers, Boca

3. Koppell GO 1994 "Toxic fairways: risking groundwater contamination from pesticides

4. Statistics Canada - Household and Environmental Practices, 1994.

5. Rea WJ "pesticides." J. Nutritional & Env. Med. 6:55-124.

6. Colborn T, Dumanoski D, Myers JP 1995 "Our stolen future." Penguin Books, London,

7. Stephens R, Spurgeon A, Calvert IA, Beach J, Levy LS, Berry H, Harrington JM 1995

8. "0rganophosphate sheep dip. Clinical aspects of long-term low-dose exposure."

9. Friedman A, Kaufer D, Shemer J, Hendler 1, Soreq H, Tur-Kaspa 1 1996

10. Abou Donia MB, Wilmarth KB, Abdel-Rahman AA, Jensen KF, Oehme FW, Kurt TL

HRM should take a precautionary approach to reduce the risks to people's health and well being associated with these chemicals.

As there are options available to the public for the prevention and treatment of pest problems in lawns and shrubs, the majority of the members of the Pesticide By-law Advisory Committee proposes that HRM state in the bylaw the existing policy of no pesticide use on municipal properties, and adopt a program consisting of phase-out of cosmetic use of pesticides on lawns and gardens throughout the community and on residential properties over a four year period or less, coupled with an educational program. The latter would be designed to make people aware of the initiative and educate them about alternative pest prevention and control techniques. A program similar to that undertaken for the graded introduction of separation of compostable materials is envisaged.

1. The proposal put forward by the Advisory Committee is supported but in our opinion should be part of a, progressive phase out leading to a total ban. This includes provisions directing HRM to establish a registration system for those who have a medical letter identifying them as being at risk from involuntary exposure to pesticides. The letter should state, "it is inadvisable for this person (name) to be near pesticides for health reasons." The purpose of the registration system is to create 100 metre exclusion zones around those with a medical letter. In these buffer zones, the use of outdoor pesticides would be prohibited and notification for any outdoor pesticide program by either residents or landscapers would be required (as per the same notification system agreed upon by the committee-of-the-whole).

 

2. HRM's policy of using no pesticides on municipal properties, in effect prior to this bylaw, should be reaffirmed and explicitly stated.

 

3. In the interests of offering some protection to areas where children spend many hours each day, a 100 meter no-pesticide zone around all schools and day cares should be put into effect.

 

4. Any playground or park that has pesticides used within 100 meters around it should have a sign posted at all entrances and sides of the area in advance of the application, so people can determine for themselves if it is safe for their child to use. The sign should read: "Warning: Pesticides have been used within 100 metres of this site. Use caution." This zone should become pesticide-free as soon as possible.

 

5. We discourage the use of solid phased products or timed release pesticide products that persist for longer periods of time (many days or weeks) and make notification for avoidance unmanageable.

 

6. Begin monitoring for compliance. A good model of enforcement can be found in the Chelsea Pesticide Bylaw (attached).

 

1. In the third year of the phase-out, a 100 metre exclusion zone should be instituted in and around parks, senior citizen residences, universities, churches, hospitals, drinking water wells and waterways and the property of any citizen who requests it.

 

2. Prohibit pesticide applications near any bus stop, mailbox, or facility with a post office.

 

3. Pesticide applications should be limited to spot spraying (defined as up to one tenth of the property area).

 

4. Bark mulches treated with pesticides release vapors for many months because of their large surface area; they should be considered timed-release pesticide products and prohibited.

 

5. Hands on public education program should be undertaken for residents of HRM, similar to that developed when the ban was instituted on compostables and the green carts were introduced. Education should include non-residential properties adjacent or surrounding residential properties. For example all clinics, churches and businesses will be contacted to stop spraying and offered information on alternative approaches. Civic pride in a "clean and green" community should be encouraged.

 

Complete ban on pesticide usage for cosmetic purposes within HRM.