Dan Nosowitz in Modern Farmer offers some insights on the recent class action lawsuit filed against California winemakers. The plaintiffs found that some inexpensive wines contained arsenic at levels exceeding the federal drinking water standard for this substance. Nosowitz rightly points out that the standard is for water, not wine and “people don’t, or shouldn’t, drink as much wine as water.”
Well, let’s not go that far… kidding of course! Moderation is surely a good idea when it comes to alcohol consumption. Yet even if you drank as much wine as you do water, there’s still no reason to be alarmed about arsenic. The levels in wine are still too low to have any significant adverse impacts, and ironically, such small amounts might even have health benefits.
Arsenic is an element that naturally occurs in the earth’s crust, so traces of arsenic inevitably appear in food and water. Certainly, high levels of arsenic are not healthy and concentrated exposures can be immediately deadly. But the trace levels found in water and food are rarely an issue. Problems have emerged primarily in developing nations like Bangladesh where poor people drink from untreated water sources with arsenic levels that range in the hundreds of parts per billion (ppb), and sometimes more than 1,000 ppb.
It’s worth noting that the levels allegedly found in wine are reportedly just five times greater (or 500 percent higher as noted in the press) than the federal drinking water standard of 10 ppb. So, some number of samples—we don’t know how many—tested by the plaintiffs in this case had some level of arsenic near the 50 ppb level. But did you know that until 2006, that was the allowable level in drinking water in the United States and it had been for decades?
The U.S. Environmental Protection Agency (EPA) changed the standard to 10 ppb in 2001 with full compliance not required until 2006. The 10 ppb standard for arsenic in drinking water is excessively overcautious. When EPA proposed it, it was very controversial because the cost to small drinking water systems was substantial and the benefits highly questionable. EPA’s Science Advisory Board highlighted lots of problems with EPA’s science and maintained that the change could actually undermine public health. The SAB explained that the costs might cause some small communities to disconnect their water systems, forcing people to use untreated well water, but EPA finalized the rule anyway.
If you look at the history, you can see that EPA did not change the standard for safety reasons; they did it for political ones. You may remember, environmental activists attacked the Bush administration for taking time to reconsider changing the standard, which the Clinton administration rushed out during the final hours of the Clinton presidency. Green groups made it sound like the Bush administration was adding arsenic to the water supply. And this bad press made a rational and scientific debate impossible.
A panel of scientists had reviewed the issue for the National Research Council, which the National Academies Press published in 1999. If you read this report closely, it showed that there was little justification for changing the 50 ppb standard. The report noted (see page 7): “No human studies of sufficient statistical power or scope have examined whether consumption of arsenic in drinking water at the current MCL [50ppb] results in the incidence of cancer or no cancer effects.” In other words, there was no evidence that anyone ever suffered ill effects from water that complied with the 50 ppb standard in the United States, which was set in 1942 by the Public Health Service and became an EPA standard in 1975.
Ironically, the NRC report became part of the insanity because the executive summary was written by just a couple of the panel members, and it did not reflect the conclusions in the report itself. The summary exaggerated risks from trace level arsenic in drinking water—and that’s what the media latched on to. Several scientists who served on the panel for the report complained to EPA about the report’s ridiculous conclusions that appeared in its executive summary.
It was clear that EPA did not have data on the impact of arsenic at trace exposures common in U.S. drinking water. Instead, the agency justified its rule based on theoretical risks extrapolated from studies of malnourished populations in Taiwan that were exposed to arsenic in water for decades at levels that were multitudes higher than that of U.S. exposures. EPA’s own Science Advisory Board pointed out that EPA’s approach greatly overestimated risks by making such extrapolations.
In addition to the inadequacy of these Taiwanese studies is the fact that EPA used a linear-no-threshold (LNT) model to assess arsenic risks. This model assumes that if a chemical is dangerous at high levels, then it must be dangerous at low ones. But that’s not always the case. An alternative model is the threshold model, which maintains that there is a threshold level at and above a chemical might cause adverse health effects, while lower levels pose negligible risks.
There are many good reasons to believe that such thresholds exist, and that threshold theory makes more sense than LNT models. But there is also a third possibility referred to as hormesis, which may apply for some substances including arsenic. Toxicology Dr. Edward Calabrese explains it thus:
Enter an alternative model, which claims that the fundamental shape of the dose–response curve is neither linear nor threshold, but rather U-shaped. …This model not only challenges the LNT and threshold models but, more importantly, it suggests that as the dose decreases there are not only quantitative changes in the response measured but also qualitative changes. That is, as the dose of a carcinogen decreases, it reaches a point where the agent actually may reduce the risk of cancer below that of the control group.
There is a growing body of science that finds hormesis applies to arsenic; the element appears to be beneficial at low levels and deadly at concentrated high levels. A recent study, produced by Dr. Allen Smith of the University of California at Berkeley and his colleagues found that breast cancer rates declined by 50 percent in an area of Chile where arsenic in the water supply reached as much as 800 ppb. Dr. Smith, who ironically was one of the most ardent supporters of EPA’s strict arsenic standard, reports:
“What we found was astonishing,” said study lead author Dr. Allan Smith, UC Berkeley professor of epidemiology and director of the Arsenic Health Effects Research Program. “We’ve been studying the long-term effects of arsenic in this population for many years, focusing on increased disease and mortality attributed to the historical exposure to arsenic in this population.”
Now Dr. Smith is involved in research on how to use arsenic to treat cancer! UC Berkeley reports:
As part of the study, researchers at the Stanford Cancer Institute found that human breast cancer cells grown in lab cultures are killed by arsenic, and normal breast cells are more resistant to arsenic. The medicinal use of arsenic is not entirely new. Arsenic trioxide was approved in 2000 by the Food and Drug Administration as an effective treatment for a rare type of leukemia. So should arsenic now be used to treat breast cancer? “Not yet,” said Smith. “We do not know if the treatment will work, but carefully designed clinical trials should take place as soon as possible based on this new evidence.”
Despite Smith’s astonishment, these findings are not completely surprising. The breast cancer finding offers one example of possible hormesis and is part of a growing body of evidence that arsenic may be beneficial at low levels.
But of course, the high levels of arsenic in some of Chile’s drinking water was not good. Some studies report adverse health effects associated with this water. Research needs to focus on finding the levels that provide benefits without ill effects.
In any case, the levels of arsenic reported in this lawsuit are nowhere near levels shown to cause adverse health effects. And who knows… one day we may be able to show with some certainty that such trace exposures are beneficial!