TCS Daily

Bugging Out

By Kenneth Green - June 10, 2003 12:00 AM

An increasing number of localities in North America are banning or restricting "ornamental" or "cosmetic" pesticides," the chemicals used to protect people's lawns, gardens, and trees.

In the United States, the Environmental Protection Agency has restricted or banned several ornamental pesticides, including Dursban and Diazinon. Cities, such as San Francisco and entire states, such as Maryland, have placed severe restrictions on the use of ornamental pesticides. In Canada, ornamental pesticides such as 2,4-D and MCPP have been partially banned in Halifax, Nova Scotia; and completely banned in some parts of New Brunswick and Ontario. On May 23rd the city of Toronto passed a bylaw that would ban the use (but not the sale!) of ornamental pesticides.

Pesticide alarmist groups such as PANNA, the Pesticide Action Network of North America, campaign for bans and restrictions on commonly used pesticides and claim that "Pesticides are hazardous to human health and the environment, undermine local and global food security and threaten agricultural biodiversity." But is this claim true? The Heartland Institute's James Taylor has observed that banning ornamental pesticides used at parks and schools will expose people to higher levels of risk from disease-carrying pests, such as roaches and mosquitoes, or to stinging insects that can trigger lethal allergic responses, such as fire ants and wasps.

Two questions are key to evaluating the attractiveness of ornamental pesticide bans: Are pesticide bans protective? Are pesticide bans harmful?

Are Pesticide Bans Protective?

Though proponents of pesticide bans imply that routine exposures to low levels of pesticides are harmful, evidence doesn't back them up. Canada's Fraser Institute recently published "Misconceptions about the Causes of Cancer," in which noted UC Berkeley toxicologists Lois Gold and Bruce Ames point out that synthetic chemicals, such as pesticides, are no more toxic than natural chemicals made by the plants we consume every day. Gold and colleagues use data from rodent tests to rank the cancer hazard of synthetic and natural pesticides, called the "HERP" index. The table below shows how a few synthetic pesticides stack up alongside some of the common chemicals in our foods, medicines, and in our environment.

It's clear that pesticide exposures do not pose a significant risk when compared to the many other chemicals, both natural and synthetic, that we encounter every day. A single sleeping pill poses a cancer risk that is over 150 million times higher than routine exposures to pesticide residues.

Are Pesticide Bans Harmful?

Measures to reduce risk are rarely pure in their impacts on risk - tradeoffs are the rule, rather than the exception. The same holds true for ornamental pesticide bans. Four fairly obvious risk tradeoffs are easily apparent.

Pests and weeds are pests and weeds: The reasons that people use pesticides and herbicides in their gardens and homes are pretty intuitive: to reduce the quantities of insect pests and allergenic weeds in the environment. Insects are notorious carriers of many kinds of disease, and controlling them in the lawn and garden is an integral part of keeping them out of the house. Allergic reactions to insect stings and bites cause a small number of deaths every year, and worries about tick-borne and mosquito-borne diseases are growing across North America. In addition, weeds can aggravate allergic conditions, aggravating asthma and other respiratory conditions.

Home-brew dangers: Various groups arguing against pesticides are promoting home-brew alternatives, such as solutions made from rhubarb. One recipe calls for steeping rhubarb leaves in water. But as the Medline Medical Encyclopedia points out, rhubarb leaves contain oxalic acid, a highly toxic chemical that can cause weakness, burning in the mouth, difficulty breathing, stomach or abdominal pain, nausea, vomiting, diarrhea; seizures and coma. Conventional pesticides are sold in containers that are safety-capped, well labeled, with explicit instructions about care, storage, and treatment for accidental ingestion. Bottles of home-brew pesticide will not have such safeguards, and it's not unreasonable to presume that accidental ingestion would be more likely, rather than less.

Fruit and vegetable consumption is protective. As Lois Gold and Bruce Ames have pointed out for decades, fruits and vegetables are important sources of health-protective, and cancer-fighting vitamins and minerals, including folic acid and vitamin C. Though information is scarce about how many people grow fruits and vegetables for consumption, and an interesting poll from Canada suggests that the number is significant. According to Canadian polling firm Ipsos-Reed, one poll found that 44% of people in greater Vancouver live in households that grow some of their own food. If the rate is that high in highly urbanized Vancouver, it's likely higher in more suburban and rural settings. Given the high cost of fresh produce, it reasonable to speculate that people might replace their home-grown fruit and vegetables with other foods that are less health-protective.

Time is money, and money is time: Consumers use pesticides because, compared to the cost of hiring a manual gardening service, or manually pulling weeds oneself, pesticides are relatively inexpensive. At a few dollars a bottle, gardeners can buy back several hours of their time, in an age where time is already at a premium. And one can only wonder how many weekend gardeners will throw their backs out bending and pulling weeds for hours at a time, with the subsequent loss of work time and income.

Ornamental pesticide bans and restrictions seem to offer little or no health benefit, yet reduce consumer choice, increase the costs of home ownership and maintenance, hinder the cultivation and consumption of health-protective fruits and vegetables by home-gardeners, and promote the use of toxic, home-brew alternatives of unproven effectiveness.

The focus of public attention on extremely remote, hypothetical risks consumes public resources that could be better used elsewhere, and distracts people from addressing the real risk-reducing actions that require some willpower: not smoking, not drinking alcohol excessively, and eating enough fresh fruit and vegetables to reduce their vulnerability to cancer and other illness.

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