Cover Story
Toxic Inheritance
by Sarah Barnett
We must head the grim warnings from the animal kingdom about the dangers of environmental chemicals.
It’s not easy, being a frog. Their numbers have fallen worldwide by about a third since the 1950s, due to a combination of environmental impacts, but the worst problems they face – the result of sometimes swimming in a chemical soup that makes them voiceless, sterile or even hermaphrodites – could be really bad news for humans, too.
Biologist Jared Diamond has already raised the alarm about the rapid increase in human infertility in the western world. “The average sperm count of an American college student today is 80 or 90 percent below what it was 50 years ago … It is quite remarkable, and there must be a reason for it. And the reason is almost surely environmental chemicals.”
“People will introduce a chemical technology and think there’s no problem,” explains Professor Terry Collins, “then 10-20 years later they’ll start to see things in the animal record saying there is a problem.”
Collins is an Auckland University alumnus who directs the Carnegie Mellon Institute for Green Oxidation Chemistry in the US. He was recently back home as one of the university’s “distinguished alumni” to deliver a series of lectures.
The trouble with evidence in the animal record, he says, is that the industries producing the chemicals, and the governments regulating them, usually demand human health evidence before taking action, which is almost impossible to produce.
You can’t pour herbicide over a baby, then wait and see what happens. “From my point of view,” he says, “I think frogs are enough.”
Professor Tyrone Hayes has the frogs. In his University of California Berkeley lab – part of the Department of Integrative Biology – he researches the endocrine-disrupting properties of the US’s second most popular herbicide, Atrazine, also used in New Zealand.
The endocrine system is essentially the series of glands that secrete and regulate hormones in the body. Endocrine disrupters mimic oestrogen, leading to feminisation of males and a heightened risk of hormone-related cancers in both sexes, particularly breast and prostate cancers.
Hayes began the research in 1998 for Novartis, the Swiss-owned company that developed Atrazine – banned in Switzerland – by putting trace amounts in tanks where he was raising leopard frogs.
The males, once fully grown, developed problems after exposure to concentrations as exquisite as 0.1 parts per billion – one-30th of the US Environmental Protection Agency’s (EPA) “safe” level for Atrazine contamination of drinking water. Some had multiple sex organs, some had traces of egg yolk in their testes, some were hermaphrodites and still others had shrunken larynges, rendering them unable to make mating calls.
Hayes left Novartis shortly after the results became apparent.
“That’s the short version of it, yeah. What happened was I became very uncomfortable,” Hayes claims.
Novartis later became Syngenta, which continues to deny the validity of Hayes’s research.
However, Hayes’s follow-up studies, published in the peer-reviewed journals Proceedings of the National Academy of Science and Nature, found similar results in more lab frogs, as well as in wild frogs that had been collected from areas with Atrazine. Forty percent of the males were feminised – chemically castrated – and 80 percent had shrunken larynges – again, after a single exposure to low concentrations of Atrazine.
In 2003, a group of workers at a plant in Louisiana where Atrazine is manufactured sued Syngenta over a rate of prostate cancer shown to be almost nine times that of the general population. The case is pending.
Last year, the European Union banned Atrazine as part of an initiative to put the onus onto chemical manufacturers to prove their products’ safety, as new science like Hayes’s comes to light.
His current research looks beyond reproductive difficulties and into broader areas like immune function.
The EPA still maintains that the science is insufficient to ban Atrazine, although it has now asked Syngenta to monitor water in areas where Atrazine is sprayed.
You only have to look at lead contamination to see how influential industry can be, Collins says. Lead paint was banned first in Austria in 1909, but it wasn’t until 1979 that the US was fully rid of it. “Crazy. We never needed it. Could have used zinc, could have used titanium.”
Instead, paint in the 1930s was 50 percent lead by weight – “a lethal dose for a child was a square two inches either side … And people writing papers about how it was bad for kids were oppressed.”
Tens of thousands of children died in those decades, he says, and “the whole country suffered IQ deficits from lead. There’s absolutely no question.”
He’s not kidding – IQ loss can be measured exactly by how much lead is in the blood. “Purely so that a small group of people could make some more money.”
On the other hand, industrial and governmental action was swift when the damage to the ozone layer from CFCs was made apparent – there was only a two-year gap between the UN’s Montreal Protocol in 1987 to phase out CFCs and its enforcement in 1989. Although Collins is quick to say that he doesn’t want to diminish that major accomplishment at all, “one of the major producers [of CFCs] had the patents on the next generation of products that would replace it. That was also critical to it.”
Endocrine disruption puts the stakes, he emphasises, “infinitely higher” than even the historical lead contamination in the US.
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