Soil pollution refers to the presence of a chemical or substance out of place and/or present in a soil at higher than normal concentration that has adverse effects on any non-targeted organism.
Human activities over thousands of years have left a legacy of polluted soils worldwide. Much of it is local soil contamination which occurs commonly in connection to past and present mineral extraction, industrial activities, waste management and disposal, and includes remnants of hazardous materials such as obsolete pesticides. Countless chemical agents, some of them highly persistent, are found at various levels in the ground and can enter groundwater and surface water, locally produced food, and can even become airborne (gases, vapours, dusts, particulates). Soil pollution and its adverse health effects have been documented in many cases, but the magnitude of the overall impact on human health is not known. This is in contrast to air or water pollution, for which reliable estimates of their impacts have been available for two decades (FAO, 2018).
Soil pollution has been identified as one of the main soil threats affecting global soils and the ecosystem services that they provide (FAO and ITPS, 2015). Soil pollution poses a serious risk to human health through direct contact (dermal exposure, inhalation of polluted soil particles, intentional ingestion of polluted soil) or indirectly, by consuming plants or animals that have accumulated significant amounts of soil contaminants (FAO, 2018). For example, in an area of Japan where soil has been contaminated with cadmium from zinc/lead mines, Itai-itai disease used to be widespread and is still seen in women over 50 years of age. Itai-itai disease is characterised by osteo-malacia, osteoporosis, painful bone fractures and kidney dysfunction (WHO, 2019). Health risks associated with the widespread soil pollution by radionuclides released during the Chernobyl disaster in 1986 are an enduring memory for many people (Rodríguez-Eugenio et al., 2018).
Despite efforts in many regions of the world to estimate the extent of soil pollution, the lack of harmonised and comprehensive data at national, regional and global level limits the mobilization of economic resources to minimise soil pollution and to achieve public and private commitment to combating soil pollution. There is a need to translate sound scientific evidence into concrete actions to prevent, control and remediate soil pollution (FAO, 2018).
Remediation of polluted soils is essential, and research continues to develop novel, science-based remediation methods. Increasingly, expensive physical remediation methods such as chemical inactivation or sequestration in landfills are being replaced by science-based biological methods such as enhanced microbial degradation or phytoremediation (Rodríguez-Eugenio et al., 2018). The maintenance of soil health and the prevention and reduction of soil pollution are possible through promoting sustainable soil management practices, environmentally friendly industrial processes, reduction of waste generation, recycling and reuse of goods, and sustainable waste storage (FAO, 2018).
The risks to human health posed by contaminated soils is assessed by comparing a representative soil concentration with chemical specific assessment criteria indicative of ‘safe’ levels of exposure. There is no international standard for deriving these criteria. For example, Jennings (2013) compared the range of American standards with standards used elsewhere around the world. A total of 5949 guidance values for 57 elements were identified across the US regulatory authorities and assessment criteria values were seen to have been published in at least 71 other United Nations member states.
From the students of SSOU “Dimitrija Cupovski” Veles, North Macedonia