Water contaminated through unsustainable agricultural practices pose serious risks to human health and ecosystems of the planet, often underestimated by policy-makers and farmers, said in a new report.
According to a Global survey of water pollution in agriculture, “More people, more food, worse water?”, FAO and the International water management Institute conference in Tajikistan (June 19-22), are currently the main sources of water pollution in many countries are no cities or industry, and agriculture, as the most common chemical pollutants found in groundwater aquifers worldwide are agricultural nitrates.
The report States that modern agriculture is responsible for recovery operations of large amounts of agrochemicals, organic chemicals, sediment, and saline solutions.
This pollution affects billions of people and entails annual costs exceeding billions of dollars.
“Agriculture is the largest by volume producer of sewage and livestock produce much more waste than people. As the intensification of agriculture in the countries has increased significantly the use of synthetic pesticides, fertilizers and other substances,” they write in the Preface to the report, Eduardo Mansur, Director of FAO’s land and water, and Claudia Sadoff, Director General of IWMI.
“Despite the fact that it contributed to the growth of food production, these factors also led to the growth of environmental threats and potential problems for human health,” they added.
Agricultural pollutants that cause the greatest concern are pathogens from livestock production, pesticides and nitrates in groundwater, trace elements metals and accumulate pollutants, including antibiotics and resistance genes to antimicrobial drugs secreted by animals.
To eliminate information gaps, policy and decision-making at the farm level in the new report presents the most comprehensive overview published to date, and before the scattered scientific literature on this issue, now generalized into a single link.
How agriculture affects water quality
The global boom in agricultural productivity after world war II has largely been achieved by the intensive use of chemicals such as pesticides and chemical fertilizers.
Since 1960 the use of mineral fertilizers has increased ten times since 1970, global trade in pesticides has grown from one to 35 billion dollars a year.
Meanwhile, the intensification of livestock production and the global population has tripled over the period since 1970 has led to the emergence of a new class of contaminants: antibiotics, vaccines and hormones — growth promoters, who farms together with water get into the ecosystem and into the water we drink.
Besides organic matter from livestock production systems is currently much stronger than pollute the water than urban organic pollution.
Another rapidly growing sector — aquaculture (which has grown since 1980, twenty times) now resets to surface water large amounts of fish excrement, uneaten feed, antibiotics, fungicides and anti-fouling agents.
What can be done
Water pollution agriculture is a difficult challenge and an effective solution requires a number of responses, in accordance with the report, “More people, more food, and worse water.”
The most effective way to reduce pressure on aquatic ecosystems and rural environment is to limit the discharge of pollutants from sources or intercept them before they get to vulnerable ecosystems. Beyond farms, the costs greatly increase.
One way to achieve this is to develop policies and incentives — for example, taxes and subsidies, to encourage people to switch to more sustainable diets and restraining the growth of demand for food, produced with great harm to the environment.
On the consumer level you can reduce food waste. In one study, the report States that food waste is thrown away to 6.3 teragrams nitrogen pollutants per year.
“Traditional” regulatory instruments will also remain a key factor in the reduction of pollutant emissions from farms. These include compliance with water quality standards; issuing permits for discharge of pollutants; and mandatory implementation of best practices; assessment of the environmental impact of certain agricultural activities; the creation of buffer zones around farms; restrictions on agricultural practices, or the location of farms; and restrictions on the marketing and sale of hazardous substances.
However, the report acknowledges that the well known principles of reducing pollution, such as the “polluter pays”, it is difficult to apply to nonpoint sources of agricultural pollution, as the definition of the actual pollutant is neither easy nor cheap.
This means that the measures that will convince farmers to “get involved” is critical for the prevention of pollution at the origin, including tax incentives in response to the use of practices that minimize emissions of nutrients and pesticides, or payments for “maintenance of landscape”.
There are many good practices that help reduce emissions from farms in the surrounding ecosystems, including: minimizing the use of fertilizers and pesticides, the creation of buffer zones along watercourses and the boundaries of farms or the improvement of schemes for the control of drainage.
Comprehensive protection from pests that combines the use of pest-resistant crop varieties and practice crop rotation and use of natural predators of known pests is another useful tool
In animal husbandry it is necessary to use traditional techniques, such as restoration of degraded rangelands and improving the management of animal diet, feed additives and medicines. At the same time you can also use new approaches and technologies for the utilization of nutrients, such as biostable running on agricultural waste.
Water pollution in agriculture: the numbers on the note
§ Irrigation is the largest volume manufacturer of wastewater in the world (in the form of agricultural drainage).
§ In agricultural soil worldwide annually paid almost 115 million tonnes of mineral nitrogen fertilizers. About 20 percent of these nitrogen compounds ultimately accumulate in soils and biomass, and 35 percent falls into the oceans.
§ Annually in the environment around the world sprayed 4.6 million tons of chemical pesticides
§ Developing countries account for 25 percent of the volume of pesticides used in world agriculture, the pesticides are the cause of 99 percent of the deaths in the world.
§ Recent estimates show that economic damage caused by pesticides to non-targeted species (including humans) in developing countries is nearly 8 billion USD per year.
§ Lack of oxygen (hypoxia) from anthropogenic pressures in the production process of food is recorded on the area of 240,000 km2 worldwide, including 70 000 km2 of inland water and 170 000 km2 of coastal areas.
§ It is estimated that nearly 24% of irrigated areas in the world prone to salinization.
§ Currently, the list of substances found in the European aquatic environment — more than 700 new pollutants, their metabolites and transformation products.