Management of the environment is not a recent development in human history. For thousands of years, human societies have been learning how to manipulate and control the natural processes of this planet, and while full control of nature is not possible, the god-like technology we possess often produces the illusion that we can. Now we are essentially in the process of picking up the pieces of the environment; and many believe the solution is found exclusively in the innovations of the last half-century. But Randhawa and his team approach the world’s environmental problems with a different, more traditional mentality. Using the Vedic literature as their guide, this group of researchers investigated and reviewed the bioremediating capabilities of cow dung, and how it can remove harmful pollutants from various contaminated sites through biodegradation. A main aim of their study is to provide a framework for future research into this cheap, safe, and accessible remediation method, especially in developing countries that cannot afford expensive waste-management machinery. Among its many applications, cow manure has the ability to breakdown pharmaceuticals, pesticides, and petroleum products when applied to the soil or water in the proper way. While this paper did almost none of its own fieldwork, it compiled information from several sources and allows other researchers to carry out similar projects in their region.—Edward McLean
Randhawa, G. and Kullar, J., Bioremediation of Pharmaceuticals, Pesticides, and Petrochemicals with Gomeya/Cow Dung. ISRN Pharmacology, vol. 2011.
The authors of this study approached their research in a slightly unconventional way: they consulted ancient texts from India known as the Vedic literature, which list all the medical and scientific understanding and knowledge from roughly 1200 years ago. Among this information is an account of the many applications of cow milk and dung, and how they can be used to rejuvenate or clean up different contaminated sites, like soils with excessive heavy metals or oil. It would seem that these ancient people were quite aware of the remediating capacity of cow dung. But interestingly, Randhawa and Kullar read further into the ancient texts and are convinced that the species of cow that produces the manure matters, and the most effective breed is the indigenous Indian cow. They found that the zinc, copper, phosphorus, and calcium content in the indigenous cow, versus a cross-breed, was markedly higher. Having established the proper treatments, Randhawa and Kullar catalogued, and in many cases tested, existing research into the environmental applications of cow dung and the methods to properly use it in decontamination projects.
The authors of this study list at least seven different ways that manure can degrade or help degrade environmental pollutants like compounds in pharmaceutical and biomedical waste, heavy metals from municipal sludge, excess hydrocarbons from oil found in the water and soil, and a variety of other contaminants. One especially simplistic and effective procedure is the removal of arsenic from potable water sources using just manure, sunlight, and filtration. This harmful element is separated from the water through several rinses and then put into a small ditch with dung on top. The microorganisms convert arsenic to gaseous arsine, which is not necessarily environmentally safe, but at least it is not in the drinking water. Another remarkable quality of cow dung is its ability to degrade harmful hydrocarbons and other compounds found in crude oil quickly and effectively, many of which are carcinogenic and/or non-biodegradable. Benzene is one of those compounds, yet one species of bacteria, Pseudomonas putida, is able to degrade this hydrocarbon quite successfully and rapidly.
One area of research in which they showed a particular interest was the bioremediation of pesticide residue and runoff. India is one of the largest pesticide producers in the world, generating roughly 90,000 tons a year. Most of these compounds are harmful carcinogens and as much as 97 – 98% remains in the soil and ground water, slowly accumulating, trickling up through all trophic levels. Randhawa found that several members of the microbial community of cow manure can work together to degrade several of the more harmful chemicals in the pesticides. This process is not fully understood and that is perhaps the most promising realization to take away from bioremediation projects. Bacteria have been evolving mechanisms to digest every manner of energy that they encounter for nearly as long as life has existed on this planet. They can work separately or in concert to break down so many different anthropogenic compounds. Instead of creating powerful machines that sometimes might be seen as more destructive to their cause than helpful, we might want to start using what exists naturally. Maybe then we will start taking baby steps towards the natural equilibrium this planet so desperately craves.