The biggest issue facing the use of chemical fertilizers is groundwater contamination. Nitorgen fertilizers break down into nitrates and travel easily through the soil. Because it is water-soluble and can remain in groundwater for decades, the addition of more nitrogen over the years has an accumulative effect. At the University of Wisconsin, Madison, they discovered the effects of chemical fertilizers are compounded when mixed with a single pesticide. They discovered altered immune, endocrine and nervous system functions in mice, as well as influence on childens and fetuss developing neurological, endocrine and immune systems. These influences portend change in ability to learn and in patterns of aggression.73 One popular fertilizer, urea, produces ammonia emanation, contributes to acid rain, groundwater contamination and ozone depletion due to release of nitrous oxide by denitrification process. With its increased use and projections of future use, this problem may increase several fold in the coming decades.105 Groundwater contamination has been linked to gastric cancer, goitre, birth malformations, and hypertension107; testicular cancer108 and stomach cancer.109 Excessive air- and water-borne nitrogen from fertilizers may cause respiratory ailments, cardiac disease, and several cancers, as well as can inhibit crop growth, increase allergenic pollen production, and potentially affect the dynamics of several vector-borne diseases, including West Nile virus, malaria, and cholera.110 Perhaps one of the scariest effects of chemical fertilizers is something called methemoglobinemia. In infants it is alternatively known as Blue Baby Syndrome. The risk most often occurs when infants are given formula reconstituted with nitrate contaminated water. The condition causes a decrease in oxygen in the blood and results in a blue-grey skin color, causes lethargy and/or irritability and can lead to coma or death.111 Ive been unable to find whether the same risk exists for breastfeeding babies whose mothers drank contaminated water. Nitrogen groundwater contamination also contributes to marine dead zones. The increase in the water-soluble nitrates creates an influx of plant-life, which eats up oxygen and starves out fish and crustaceans. This has an impact not only on the aquatic ecosystem, but on local societies who depend on food sourced from those areas. 106 And then there is the highly questionable use of raw sewer sludge as a fertilizer. Yes, you heard me right. In some countries, raw, uncomposted and untreated human waste is applied directly to crops and soil, a practice known as night soil since its typically applied at night. The risk of disease is obvious and high112, 113 and this practice should never be confused with humanure, a long, highly involved process of decomposing human waste into a safe resource.
Posted on: Sat, 09 Nov 2013 12:42:05 +0000
Trending Topics
Recently Viewed Topics
© 2015