Soil contamination with Arsenic - risk element transfer from soil to plant.

Stella Beate Lukste

Bachelor's thesis

Abstract:

Soil contamination with toxic risk elements (RE) is recognized as a global problem that can cause serious damage to both environment and human health. Arsenic is one of the RE that can cause serious health risks even when present in small amounts.The contaminant can reach the soil through lithogenic (geological; parent material; volcanic activity; trace elements) and anthropogenic sources (industrial waste; mining activities; agri-chemicals). The main natural source in soils is weathering from parent materials. Arsenic also occurs as an impurity in mineral ores and as a result of mining and other industrial operations. Total As soil concentrations in solid soil phase range between 0,1 - 55 mg kg-1 in uncontaminated soils. As (III) and As(V) are major species found in most soil samples, however As(III) is 60 times more toxic than As(V). Arsenic can cause acute and chronic poisoning for humans. If ingested, the absorbed As accumulates mainly in the liver, kidneys, heart and lungs. The contamination pathways can be from As dust, contaminated water or also As that has accumulated in plant parts.There are some plants that rapidly reduce As(V) to As(III) inside cells, however, the amount of As accumulated and also the plant part in which it is accumulated varies greatly between species. Generally, leafy vegetables tend to be “accumulators” and fruity vegetables tend to be “excluders”. From cereals the highest accumulation rate is for rice. Rice is one of the most important staples in many countries, therefore there have been several studies focusing on reducing and preventing the As accumulation in rice.In general, there are different ways to prevent As accumulation in crops, such as water regime management, mitigation, amendment and fertilization practices. There are also possible ways of remediation of As contaminated soils, which include methylation, use of soil fungal species and hyperaccumulating ferns (Pteris vittata and Pityrogramma calomelanos).

Keywords

Soil contamination, Arsenic, Toxicity, As accumulating plants

Language used: English

Date on which the thesis was submitted / produced: 16. 7. 2020

Thesis defence

• Supervisor: doc. Ing. Ondřej Drábek, Ph.D.

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Bachelor programme / field:
Agriculture and Food / Agriculture and Food