Tuesday, February 24, 2015

Pesticides good and bad, and be very afraid of oxidane

Pesticides have impacts, and improperly used, some pesticides can be health hazards. No question about that. 

In the Islands, it’s become a meme in some groups that pesticides are necessarily awful. But as usual, black and white don’t serve us well in this discussion. The reality falls in the gray.

It’s also true that properly used pesticides can do more good than harm—they preserve our food, remove unwanted pests, protect us from diseases carried by vermin, help control the spread of allergens, and on and on.

In recent discussions, I’ve heard assertions that this man-made compound is an endocrine disruptor, and that compound causes birth defects, and another causes cancer. 

In many case, that may be true. It’s also true that endocrine disruption and birth defects and cancer occurred before modern pesticides were developed. 

Natural products can be associated with those conditions, too. Examples: soy for endocrine disruption; German measles for birth defects; sunlight and tobacco for cancer.

And, of course, there are genetic causes or increased sensitivities for these. See here, and here. Some individuals and families have a natural sensitivity to some endocrine disruptors.

What are we to make of all this? From my perspective, we should accept that nothing in this field is simple, and you are likely to be misled if you listen to people who claim it is simple.

Linda S. Birnbaum, director of the National Institute of Environmental Health Sciences, told a U.S. House of Representatives committee that her agency is seriously concerned about groundwater contamination. 

If you listened to much of the debate in Hawai`i, you might think agricultural chemicals were the only man-made products entering our groundwater. It’s not only agricultural chemicals, but also pharmaceuticals, sunscreen, flame retardants, plastics, cosmetics. All can be endocrine disruptors.

“Endocrine disruptors are naturally occurring or man-made substances that may mimic or interfere with the function of hormones in the body. Endocrine disruptors may turn on, shut off, or modify signals that hormones carry and thus affect the normal functions of tissues and organs,” she said. 

“Both naturally occurring and manmade substances can be endocrine disruptors,” Birnbaum said.

Other chemicals that pollute the groundwater? 

If you get enough people in a community drinking coffee, tea, and cola, then you’re likely to find caffeine—a pesticide—in the groundwater. A 2006-2007 survey on Kauai found caffeine in North Shore groundwater and streams anywhere downstream from human development.

It is possible to make a case against anything, but it may or may not be a valid case, and it may lack perspective.


Some entirely natural pesticides are far more dangerous than man-made ones. Take the natural pesticide in the castor bean plant, which can kill anything that eats the seed—aphids and ducks and horses and humans alike. The scientific name of castor bean is Ricinus communis . The poison is one of the most dangerous products in chemical warfare, ricin.
Another example:

A real bad guy is the chemical oxidane. It can cause death in minutes through inhalation. In its gaseous form it can burn the skin. It can be a greenhouse gas. It corrodes metals. It is an industrial solvent that is used in pesticides and nuclear plants. 

Not hard to make a case against oxidane with that information. Yet it is found in all our water supplies. For good reason. Oxidane is, of course, a scientific name for water.

In some of our Hawaiian legislative deliberations, we’re considering tossing the safest and the most dangerous chemicals in the same regulatory basket. That doesn’t make sense. 

This is not to say we should not apply rigorous testing to pesticides, and to require protective measures in their use as appropriate. 

It is to say this about making public policy: We are better served if we apply careful scientific discipline than if we heed slogans that fit on protest placards. 

© Jan TenBruggencate 2015

1 comment:

Anonymous said...

Thanks Jan, I agree. This whole "GMO" debate really ought to be about pesticides and it's much more of a grey issue than the black and white most people paint it to be.