Biosolids: they are what you eat

In our stories “The sludge hits the farm” (October 22) and “Biosolids big bucks” (November 26), we took note of a product called biosolids, consisting of processed human sewage and municipal wastewater, which is being used both locally and nationwide as fertilizer. The articles articulated some problems related to this practice; in particular, due to ingestion of pharmaceuticals and pesticide-laden food by humans as well as poisonous substances in cleaning products flushed down the drain, biosolids may contain various toxins. Complete analyses of possible toxins contained in biosolids do not seem to be available, and there is no requirement that the use of biosolids in products sold to the public, like garden manure, be disclosed.

We think it is important to address these problems. Nevertheless, the processing of human sewage and its reuse for fertilizer strikes us as a step in the right direction. There are six and a half billion of us and counting on this planet, and if we don’t find some way to recycle our waste productively, we are going to suffocate in it.

The practice of using human excrement for fertilizer is not new. Indeed, it was the norm in most parts of Asia for thousands of years, until quite recently. And while modern science has informed us of some dangers of this practice, such as the possibility of E-coli infections in the food we put on our table, it may well also provide us with the tools to avoid these problems.

The ideal sustainable way to maintain fertility in the fields is probably the use of cover crops, since that solution avoids the runoff of elements like nitrogen that are currently destroying ecological balances in water bodies around the globe. But that’s an argument that can be made against any applied fertilizer, whether manufactured or natural. Recycling human excrement as fertilizer seems the most natural way to handle it sustainably, and we think it’s worth taking another look at how to make it work.

Such steps would include making comprehensive analyses of biosolids to detect the toxins present, from cleaning chemicals to pharmaceuticals. Sewage processing plants would have to be refined in such a way as to extract these toxins completely from the biosolids. The public should be fully informed as to whether products they buy contain biosolids, so it can make an informed decision as to whether to purchase them.

But from a holistic point of view, the single most effective thing we could do to improve the quality of biosolids would be to cut back on the poisons we are putting into our bodies and flushing down our drains. For example, a switch to organic growing and eating habits would eliminate the pesticides we ingest in our diet, and therefore those to be found in biosolids.

As for pharmaceutical pollution: while many modern medicines are true boons, this is on the whole a grossly overmedicated society. We prefer to pop pills than to correct diet and exercise habits, a change that would obviate the necessity for a huge proportion of the medicine that we now chow down. It might also help if we, like every other nation on earth, prohibited direct marketing of pharmaceuticals to the public, which creates a demand for drugs that are frequently superfluous. More responsible disposal of leftover medicines would also be helpful.

As more and more people crowd the planet, people have to change their way of thinking about what goes down the drain: remember, whatever goes down there doesn’t disappear, but will be back again for you and your children, or for somebody else and their children, in some form. We have grown too populous to bury it or leave it to decompose at a natural rate. The idea of using our own waste to help grow our food is in many ways a big step forward in this way of thinking, however distasteful it may appear at first glance to our cultural sensibilities. But to realize its potential of true sustainability, the process is going to need some work—starting with what we all decide to put in our mouths.

Also in this issue:

• No more bottom line for recycling

Dr. Punnybone

Arms Control