Human waste as fertilizer and irrigation in developing regions

According to a new report, 200 million farmers use human shit as fertilizer for 49 million acres of land. The study, published by the International Water Management Institute (IWMI), details how ten percent of the population, mostly in developing nations, eat grains and vegetables harvested from fields irrigated and fertilized with raw sewage. Traditional fertilizer and clean water is too expensive or simply unavailable in many places. From National Geographic:

The report focused on poor urban areas, where farms in or near cities supply relatively inexpensive food. Most of these operations draw irrigation water from local rivers or lakes. Unlike developed cities, however, these areas lack advanced water-treatment facilities, and rivers effectively become sewers.

When this water is used for agricultural irrigation, farmers risk absorbing disease-causing bacteria, as do consumers who eat the produce raw and unwashed. Nearly 2.2 million people die each year because of diarrhea-related diseases, including cholera, according to WHO statistics. More than 80 percent of those cases can be attributed to contact with contaminated water and a lack of proper sanitation. But Pay Drechsel, an IWMI environmental scientist, argues that the social and economic benefits of using untreated human waste to grow food outweigh the health risks....

In most cases, the excrement is used on cereal or grain crops, which are eventually cooked, minimizing the risk of transmitting water-borne pathogens and diseases, IWMI's Drechsel noted.

Human Waste Used By 200 Million Farmers (National Geographic)