When I eat out at a restaurant I’m inevitably asked whether or not I’d like bottled water with my meal. My answer usually depends upon the city I’m in – New York water tastes great, so I ask for tap water in Manhattan. The water in DC tastes like a swimming pool (at best), so I usually order bottled water at Washington restaurants.
But little did I realize that the water I’ve been drinking (whether from DC, NY or even from the bottle) has small traces of pharmaceutical chemicals in it. A new investigation conducted by the Associated Press suggests that most major urban water supplies are laced with tiny amounts of prescription drugs. How do the drugs get in the water supply?
Remember that water cycle you (or your kids) studied in grade school? Well, the “underground phase” is where the action happens. Drugs that we swallow pass through our bodies and some is released in our urine and stool. We flush that down the toilet and the fluid debris is treated in a sewage plant and then the water portion is released back into the water supply. Sewage plants and water filters are not designed to remove trace chemicals like heart medicines and anti-depressants, so they remain in the drinking water. Kind of disturbing, right?
Well, the good news (if there is any) is that the amounts of chemicals in the water are pretty small – we’re talking parts per trillion. Just to put that in perspective, that’s more than 1000 times smaller than the minimum amount needed for therapeutic effect from the fluoride added to the water system. And the concentration is far below the therapeutic threshold in the bloodstream for these drugs. But how do we know that tiny amounts of drug exposure isn’t harmful in some cumulative way?
Research into the potential long term effects of these chemicals in the water supply has focussed mostly upon the presence or absence of the drugs, and the concentrations at which they’re present. Animal studies (such as the “feminization” of fish exposed to environmental estrogens) and cell culture research suggest that exposure to larger concentrations of these drugs can cause negative outcomes, but to my knowledge there are no long term studies of the potential impact of very small concentrations on human health. But before we become outraged at this apparent lack of investigation, let’s think about why it’s so difficult to gather this kind of information.
First of all, concentration-wise, pharmaceuticals represent a small fraction of the thousands of man-made chemicals in the environment, including everything from pesticides to personal care products. So it’s very difficult to prove a cause and effect for any one drug’s influence – we are each exposed to a very dilute cocktail of chemicals in our daily lives, whether through the water we drink, the food we eat, or the air we breathe. How can we tease out the potential damage of one chemical over another?
Secondly, it’s pretty likely that any potential harm (from chemicals at such small doses) would take many years of exposure before a clinically measurable threshold is reached. It’s very difficult and expensive to study large groups of people over time – and it’s hard to know what their lifestyle choices may contribute to their overall chemical exposure. Over time people change jobs, change what they eat or drink, change where they live… the complex interplay of environmental factors make it hard to interpret exposures and effects.
And finally, how do we know what outcomes to look at? It’s possible that these small doses of pharmaceutical products could affect our bodies in fairly subtle ways – which again makes it difficult to measure. It’s hard enough to study cancer rates in populations, but how would we study differences in physical or mental performance? Or slight changes in mood or heart function?
Since there’s no easy way to prove a connection between drugs in our water system and our general health and wellbeing, we are likely to be left with far more questions than answers. I think we all agree that we’d rather not be exposed to trace amounts of any chemicals in our water supply, but unfortunately the cost of filtering all potential contaminants from the water is exceedingly high. Reverse osmosis (a process currently used to reclaim fresh water from the sea) can cost as much as $1-18/gallon depending on the system in place and the country using it. While reverse osmosis could guarantee a chemical-free drinking water supply, we couldn’t afford to supply it to all Americans. And in the end, it’s still unclear if solving that part of the puzzle would improve our overall health.
I hope that we’ll find ways to reduce the chemical load on our environment, and that advanced water purification technology will become more affordable in the future. Unfortunately, trace amounts of chemicals, drugs, and pesticides are more ubiquitous than we’d like to believe. The impact they may have on our health is difficult to measure, and largely unknown at this point. Perhaps the bottom line is that we’re all connected to one another through our environment – so that granny’s heart medicines may yet live on (albeit in trace amounts) in your bottled water. All the more reason for Americans to pull together to live healthy lifestyles, control our weight, and try to prevent the diseases that are requiring all these drugs in the first place.This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.