A Toxic Nation?

Commentary, Agriculture, Rolf Penner

A recent Sun series made the case that manmade chemicals, although helpful in many ways, shorten our lives and increase our risk of contracting cancer, and that children are particularly vulnerable. But a 50-year body of scientific research does not support such claims.

Part of the series focused on blood tests done by a Toronto-based activist group. Unsurprisingly, they found infinitesimal amounts of 46 manmade chemicals in thirteen people. None of the levels reported, however, came anywhere close to the amounts necessary to cause harm to humans. All past and present findings in medical and toxicological databases confirm that lack of danger.

Some of the substances, like manganese – a trace element necessary for good health – and arsenic, occur naturally in foodstuffs. Others, like PCBs and DDT, have not been used for decades. What wasn’t mentioned was that our exposure to these and others is steadily decreasing. Like organophosphate pesticide residues on food declining 44% between 1993 and 2001, and the concentration of lead in the blood of children aged five years and under dropping five-fold from 1976 to 2000.

Another segment argued that long term, low-dose exposure to toxins is the culprit. That flies in the face of the most fundamental rule of toxicology – it is the dose that makes the poison. One aspirin and your headache goes away; one bottle of aspirin and you go away. The fact that one over time may consume numerous low doses of aspirin does not add up to a shortened life. The same applies with other low-dose exposures to toxins.

According to one source in the series lawn pesticides are clearly associated with all sorts of maladies, including non-Hodgkin’s lymphoma. Once again, the scientific literature does not back up that claim. The U.S. National Cancer Institute spent 20 years and millions of dollars testing for such a link with the most common of these, 2,4-D. No association exists between non-Hodgkin’s lymphoma and “ever having used 2, 4-D,” its analysis concluded.

The assertion that children are at risk is also misleading. It ignores the commonly known margins of safety. Levels of the substances cited as found in children must occur at anywhere from 100 to 1,000 times these amounts before they cause observable effects. Besides, between 1980 and 1998, the death rate for children aged one to four declined 50 percent. The National Cancer Institute reports that we are experiencing “dramatic declines” in childhood cancer mortality, and that its incidence is stable. Our kids have never been healthier.

The absurd exaggerations peddled by some imply that somehow, before we started making chemical products, human beings lived in a relatively toxin-free environment. That’s never been the case. We have always consumed carcinogens, often without ill effects. Bruce Ames and Lois Gold of the University of California at Berkeley estimate that the amount of residual manmade carcinogens in food is 1,800 times less than that derived from just 54 natural plant chemicals found in food.

Our average intake of coffee, for example, is 66 times more carcinogenic than that of the most dangerous present-day pesticide, ETU. Ames points out that 99.99 percent of the chemicals we eat are natural. Plants produce these to defend against insects, fungi and predators. Ames estimates that on average we ingest roughly 5,000 to 10,000 different natural pesticides.

Couple this with the people recently hospitalized after consuming organic spinach, milk, and carrot juice and that recall rates for organics are 8 times higher than conventional foods, and claims that ‘all natural’ is a healthier, toxin free choice fall apart.

Given the amount of human exposure to manmade substances, we would have seen widespread effects by now. The lack of compelling data suggests that no cause for alarm exists.

We do know that the quarter of the population that consumes the least amount of fruits and vegetables has a cancer rate twice that of those who consume the most. If we really want to lower cancer risk, we should switch the focus to that, and stop worrying about unproven, hypothetical dangers.

This article appeared in the Winnipeg Sun on October 18, 2006