Re:Arsenic in Some Bottled Water Brands at Unsafe Levels, Co...
by jandrewrogers on Sunday June 23, 2019 @06:34PM
(#20259134)
Bottled water has always had a dubious record when it comes to contamination but arsenic safety regulations have been muddied by unrelated politics.
The EPA sets the ideal level at zero (no safe level) with a max of 10ppb but it is also an essential micronutrient in mammalian biology. It is similar in profile to selenium -- highly toxic in all but microscopic doses but necessary to live. For arsenic, much of this comes naturally in water or via eating animals that drink water. Current mammalian models suggest that humans require something like 20-50ug of arsenic, equivalent to drinking a few liters of water at the current max allowed level. Nothing too controversial here, but it should cause one to raise an eyebrow when a government agency asserts that an essential micronutrient is toxic at doses low enough to cause deficiency.
Current reductions in allowed levels are part of a proxy war on mining. Geology that naturally has background arsenic levels far above this limit is also correlated with minerals worth mining. Even if the mining is done cleanly and releases no additional arsenic into the environment, you are still responsible for remediating the area to the safety standard and not the natural background level. It ends up being a de facto ban on new mining in some regions, which is the intent. Decades ago this strategy was applied to natural contaminants that are unconditionally bad for human biology, which made it easy to set extremely low safety limits. In recent years, it has been expanded to natural contaminants where the mandated levels have a sketchier basis in science.
Which isn't to say that bottled water contamination is not a problem, just that I am skeptical that the arsenic levels being discussed here are anywhere close to harmful. They are collateral damage in an unrelated political battle.
The EPA sets the ideal level at zero (no safe level) with a max of 10ppb but it is also an essential micronutrient in mammalian biology. It is similar in profile to selenium -- highly toxic in all but microscopic doses but necessary to live. For arsenic, much of this comes naturally in water or via eating animals that drink water. Current mammalian models suggest that humans require something like 20-50ug of arsenic, equivalent to drinking a few liters of water at the current max allowed level. Nothing too controversial here, but it should cause one to raise an eyebrow when a government agency asserts that an essential micronutrient is toxic at doses low enough to cause deficiency.
Current reductions in allowed levels are part of a proxy war on mining. Geology that naturally has background arsenic levels far above this limit is also correlated with minerals worth mining. Even if the mining is done cleanly and releases no additional arsenic into the environment, you are still responsible for remediating the area to the safety standard and not the natural background level. It ends up being a de facto ban on new mining in some regions, which is the intent. Decades ago this strategy was applied to natural contaminants that are unconditionally bad for human biology, which made it easy to set extremely low safety limits. In recent years, it has been expanded to natural contaminants where the mandated levels have a sketchier basis in science.
Which isn't to say that bottled water contamination is not a problem, just that I am skeptical that the arsenic levels being discussed here are anywhere close to harmful. They are collateral damage in an unrelated political battle.