There have been a few reports in the news recently about how the US government has added formaldehyde to their list of substances known to cause cancer in humans. This doesn’t really come as a surprise – the International Agency for Research on Cancer (IARC), for example, already classifies formaldehyde as a confirmed human carcinogen. But since there’s some media attention on the subject right now, and since formaldehyde exposure can occur from a variety of sources, including many consumer products, it seems a good time to look at what this classification means for the general public.
After a bit of a break, I’m getting back to my series of posts related to mercury. This time I’ll focus on methylmercury, which is generally considered to be one of the “nastier” forms, since it is relatively toxic (primarily neurotoxicity, but also believed to cause cardiovascular and reproductive toxicity at high doses) and also bioaccumulates in animals. Since the main source of methylmercury exposure is food, and in particular fish, I’ll look at how the amount of mercury in fish relates to potential effects on humans.
The news yesterday and today has been full of reports that the World Health Organization – or more specifically the International Agency for Research on Cancer (IARC) is reporting that cellphones could cause cancer. The reaction is based on a press release; the full IARC evaluation has not yet been released. Based on what is in the press release, should we be worried?
The physics of how electromagnetic fields from cellphones interact (or don’t interact) with the human body is not my area of expertise, so I’ll leave the discussions about the plausibility based on known or suspected mechanisms of carcinogenicity – the energy from cellphones doesn’t break chemical bonds in DNA, but that doesn’t mean there is absolutely no possible mechanism of carcinogenicity. Rather, I’ll look at what the IARC press release is really telling us, which is not necessarily the same thing as how the media are spinning it.