article in National Geographic about significant concentrations estrogen in our waterways. (I came upon it researching what I thought was an "urban legend" on birth control hormones being found in open sea sharks...)
This is a phenomena that has been reliably measured for probably at least the last seven or eight years. It is considered by many to be a new and significant source of dangerous pollution in our waterways.
Some articles trumpet that this pollution is the result of modern birth control medications being excreted into sewers by the women who use them. But this may not be true. Other articles claim that birth control pill-related estrogen can only account for something on the order of 1% of the amount of estrogen currently being measured.
Digging deeper is seems clear that there are probably a small number of primary sources for this estrogen: farm run off, birth control pills, soy-related compounds, natural mammalian estrogen production, and natural sources.
Farm run off typically occurs when untreated animal waste makes its way into waterways. Animals such as cows naturally excrete estrogen - both males and females. However, concentrated feed can increase the amount of estrogen (as well as other hormones) excreted.
The amount of estrogen is also affected by how the run off is processed. Typically animal waste is not placed directly into waterways but instead makes its way there through ground water. Manure and waste is often spread on fields, for example, as fertilizer.
Soy-related compounds also involve estrogen. There is a lot of debate about this. Some say the soy products for humans are healthy (low saturated fats, positive effects on heart disease) and that soy is widely consumed in Asia. However, other argue that soy is only fit for human consumption after extensive fermenting and processing and that Asian eat very little. Some argue soy has a positive benefit for breast cancer, others a negative. In any case there seems a clear estrogen element in the human processing of soy. Perhaps this is also true for animals - soy is often a component in animal feed.
The question here is what is the impact of soy processing and consumption on the estrogen levels in waterways - on this I cannot find an answer. Fortunately its seems clear there is growing scientific interest in the over all problem so hopefully someone will address this aspect.
Animals naturally excrete estrogen - even male animals (and humans). Human males taking testosterone supplements can have elevated estrogen levels (see this). Female can have increased estrogen by taking birth control pills or estrogen supplements. Consumption of soy may also increase estrogen.
So certainly there are any number of sources for estrogen. But this does not help us much pinning down what sources are a problem.
We can, however, look back at the original article. It discusses various human activities related to food consumption, drug and pharmaceuticals which can be traced to waterways via sewage. For example, vanilla, sage and thyme all have seasonal cycles where their presence in Puget Sound varies according to the season. Similarly illegal drugs, perfumes, scents, and various pharmaceuticals all can be measured.
I would imagine it should be possible to compare the relative measurements of these non-estrogen compounds in sewage plants and extrapolate from that how much estrogen is being injected into waterways directly by humans versus what is occurring from animal and natural sources.
In any case estrogen in waterways is bad - which is why I am posting this.
To date there is direct evidence that even very minute concentrations (nanograms per liter) can cause problems with fish (or humans):
Feminization of fish and also here.
It is unclear what affects these compounds, whether spices, pain relievers, anti-psychotics, antibiotics or hormones have on fish or people. Since these compounds are typically found mixed together there may also be side effects.
Water filtration and the use of chlorine do not remove these compounds either. So, if you live downstream from a city its likely you're consuming their treasure trove of chemical compounds.
It seems like this problem is finally getting the attention of the EPA, but I would not hold my breath for them to take action. Fixes appear to be involved and expensive - either on the intake or outflow end - because traditional treatment systems are not designed to handle these compounds.
Though we are talking here about minute levels here: something like 12.5 mg per olympic size-pool their affects are still potentially significant.
There is also the issue that chemicals used to make plastic bottles can induce hormonal changes in those that consume the water - but more on this in another post.
Time to buy a good water filter I think.