USE OF ENZYME ACTIVITIES TO MONITOR POLLUTION OF AGRICULTURAL LAND

Concern about environmental pollution has grown in the last few decades, amongst both specialists in the field and society at large. This concern is reflected in the numerous studies that have been published on this topic in recent years. Soil pollution has been somewhat neglected as a topic of study, relative to air and water pollution, which are considered harmful to human life. However, soil pollution is a particularly serious problem because of the impact on soil functioning and on the ecosystem as a whole. Although natural processes such as volcanic activity and weathering of the parent material contribute to soil pollution, anthropogenic activities represent the main cause of soil pollution. Apart from some accidental events, most pollution is generated by human activities such as industrial processes, transportation, construction, uncontrolled discharges, waste generation and agriculture. Agricultural land is particularly sensitive to pollution, partly because certain agricultural practices (soil preparation and tillage, soil fertilization, grazing, etc.) may affect basic soil properties, and partly because the soils usually display poor resilience. However, pollutants often reach already degraded agricultural soils and their impact will therefore be added to existing effects. The pollutants most frequently encountered in the agricultural sector include heavy metals, petroleum derived products, persistent organic pollutants, pesticides and fertilizers. Soil enzymes such as oxidoreductases and hydrolases have been widely used to investigate the impact of different pollutants on agricultural soils. However, the study findings are often inconclusive, because the impact of a given pollutant on the activity of different soil enzymes is influenced by various factors. In this report, we analyze the findings of different studies concerning pollution of agricultural soils.