Soil contamination
[3] In North America and South-Western Europe the extent of contaminated land is best known for as many of the countries in these areas having a legal framework to identify and deal with this environmental problem.
Soil pollution can be caused by the following (non-exhaustive list): The most common chemicals involved are petroleum hydrocarbons, solvents, pesticides, lead, and other heavy metals.
As it is the byproduct of sewage treatment, it generally contains more contaminants such as organisms, pesticides, and heavy metals than other soil.
[4] In the European Union, the Urban Waste Water Treatment Directive allows sewage sludge to be sprayed onto land.
say there is a need to control this so that pathogenic microorganisms do not get into water courses and to ensure that there is no accumulation of heavy metals in the top soil.
A pesticide may be a chemical substance, biological agent (such as a virus or bacteria), antimicrobial, disinfectant or device used against any pest.
Pests include insects, plant pathogens, weeds, mollusks, birds, mammals, fish, nematodes (roundworms) and microbes that compete with humans for food, destroy property, spread or are a vector for disease or cause a nuisance.
The insects damage not only standing crops but also stored ones and in the tropics it is reckoned that one third of the total production is lost during food storage.
U.S. manufacturers continued to sell DDT to developing countries, who could not afford the expensive replacement chemicals and who did not have such stringent regulations governing the use of pesticides.
There is little published evidence on this type of contamination largely because of restrictions placed by governments of many countries on the publication of material related to war effort.
[16] Health consequences from exposure to soil contamination vary greatly depending on pollutant type, the pathway of attack, and the vulnerability of the exposed population.
Researchers suggest that pesticides and heavy metals in soil may harm cardiovascular health, including inflammation and change in the body's internal clock.
Industrial or human-made concentrations of naturally occurring substances, such as nitrate and ammonia associated with livestock manure from agricultural operations, have also been identified as health hazards in soil and groundwater.
There is an entire spectrum of further health effects such as headache, nausea, fatigue, eye irritation and skin rash for the above cited and other chemicals.
[citation needed] The Scottish Government has commissioned the Institute of Occupational Medicine to undertake a review of methods to assess risk to human health from contaminated land.
[18] There are radical soil chemistry changes which can arise from the presence of many hazardous chemicals even at low concentration of the contaminant species.
The result can be virtual eradication of some of the primary food chain, which in turn could have major consequences for predator or consumer species.
Many of these effects are now well known, such as the concentration of persistent DDT materials for avian consumers, leading to weakening of egg shells, increased chick mortality and potential extinction of species.
Various technologies have been developed for remediation of oil-contaminated soil and sediments [24] There are several principal strategies for remediation: Various national standards for concentrations of particular contaminants include the United States EPA Region 9 Preliminary Remediation Goals (U.S. PRGs), the U.S. EPA Region 3 Risk Based Concentrations (U.S. EPA RBCs) and National Environment Protection Council of Australia Guideline on Investigation Levels in Soil and Groundwater.
The immense and sustained growth of the People's Republic of China since the 1970s has exacted a price from the land in increased soil pollution.
Certain input parameters such as Health Criteria Values, age and land use are fed into CLEA UK to obtain a probabilistic output.
[30] Guidance by the Inter Departmental Committee for the Redevelopment of Contaminated Land (ICRCL)[31] has been formally withdrawn by DEFRA, for use as a prescriptive document to determine the potential need for remediation or further assessment.
The CLEA model published by DEFRA and the Environment Agency (EA) in March 2002 sets a framework for the appropriate assessment of risks to human health from contaminated land, as required by Part IIA of the Environmental Protection Act 1990.
The CLEA SGVs relate to assessing chronic (long term) risks to human health and do not apply to the protection of ground workers during construction, or other potential receptors such as groundwater, buildings, plants or other ecosystems.
[33] To date, the first ten of fifty-five contaminant SGVs have been published, for the following: arsenic, cadmium, chromium, lead, inorganic mercury, nickel, selenium ethyl benzene, phenol and toluene.
It was alleged to be caused by fly ash ponds of thermal power stations, which reportedly lead to severe birth defects in children in the Faridkot and Bhatinda districts of Punjab.
[37][38] In 2012, the Government of India confirmed[39] that the ground water in Malwa belt of Punjab has uranium metal that is 50% above the trace limits set by the United Nations' World Health Organization (WHO).
