What is soil pollutant

Soil pollutants

Soil analysis for pollutant levels

New substances always find their way into our floors in new ways

Pollutants can get into agricultural soils from the air, through improper dumping of waste, floods, but also through fertilizers and pesticides. Important groups of pollutants are heavy metals and other inorganic pollutants (e.g. arsenic), organic pollutants such as environmental chemicals (e.g. hydrocarbons, dioxins), residues from pesticides, pharmaceuticals and radionuclides.

All soils naturally (geogenic / pedogenic) contain heavy metals and radionuclides, regionally different depending on the raw material of the soil formation. Organic pollutants do not naturally occur in soils. Pollutants can inhibit the growth of crops and soil life or enter the animal-human food chain via food and feed. How much of the pollutants in the soil is transferred to the plant depends not only on the level and type of pollution, but also on soil properties such as soil type, humus content and acidity (pH value).

Load on soil and plants

In the past, a lack of environmental standards in the handling of environmentally hazardous substances led to soil contamination and contaminated sites. Agriculturally used soils are also affected. In individual cases, the Federal Soil Protection Act requires a record of soil contamination, a risk assessment for the soil-plant path and, if necessary, concepts of measures for future agricultural use. Organic pollutants such as perfluorinated surfactants (PFT) are currently being discussed.

Notified laboratories for investigations in the area of ​​soil contaminated sites - nationwide laboratory list

Research projects and publications

Pollutant inputs from agriculture

Research projects and publications

With mineral fertilizers, liquid manure, fermentation residues from biogas plants, biomass ash, biowaste and sewage sludge, not only desired nutrients can get into the soil to varying degrees, but also undesirable pollutants. Plant protection products serve to protect crops from pests and harmful weeds. However, undesirable PPP residues can remain in the soil or be relocated.

Block plant wood chip heating

In connection with climate protection, the use of the renewable energy source wood is becoming increasingly important. Wood ashes contain calcium, magnesium, potassium and phosphorus as plant nutrients, but also have different levels of pollutants depending on the type and age of wood, and the amount of bark and greenery (including natural wood). The pollutant content usually increases from the combustion chamber via the cyclone to the filter ash.
In cooperation with the State Office for the Environment, the State Agency for Agriculture and the State Agency for Forests and Forestry, the enclosed leaflet "Recycling and disposal of wood ashes" was created.
The subject of the leaflet is ashes from the combustion of natural wood. Natural wood is the main input material in municipal, commercial or private firing systems, e.g. as wood chips, residual wood from the wood processing industry or split logs.

The leaflet contains information on the properties and ingredients of wood ashes. The focus is on the various legal provisions / ordinances and technical recommendations for the recycling of ashes in agriculture and in the forest. Other recycling and disposal options are also shown.
The leaflet solves the z. The draft of the StMUG "Information sheet recycling and disposal of ashes from renewable raw materials" (as of October 2002, not published), which is partly used in practice.

Recycling and disposal of wood ash - leaflet 221 KB

Slurry spreading close to the ground

In Bavaria, around 7.8 million tonnes of pig manure are produced every year, which are applied to agricultural land as farm-own fertilizer. The aim of a research project funded by the Bavarian State Ministry for Food, Agriculture and Forests (duration 2002-2005) was to record potentially environmentally and health-relevant substances (pharmaceuticals, in particular antibiotics, heavy metals) or microorganisms and their behavior in the soil and their effects to evaluate soil organisms.
For this purpose, on the one hand, so-called “slurry monitoring” was carried out, which was primarily intended to show the contamination of slurry from Bavarian pig farms with heavy metals / trace elements and antibiotics as well as antibiotic-resistant microorganisms and resistance genes. On the other hand, practical experiments and field tests with chlorotetracycline and sulfadiazine should clarify the whereabouts (sorption, degradation, relocation) of the substances in the soil and their effect on lumbricides, collembola and soil microorganisms as well as the question of the persistence of resistance genes in the soil.
The research project was carried out by the Department of Animal Hygiene at the Technical University of Munich and the Bavarian State Institute for Agriculture (LfL).

At the 5th cultural landscape day of the LfL 2006, the most important results of the research project were presented. Further topics were the occurrence of antibiotics in water and the possible transfer to food of plant and animal origin. Measures to reduce antibiotic residues and heavy metals / trace elements in manure were presented and discussed.

Pig manure - a source of potentially undesirable substances? (LfL series of publications)

Residues, pollutant levels and hygiene parameters

In connection with the agricultural utilization of compost and fermentation residues, the question of possible pollution with inorganic and organic pollutants also arises again and again. Since 2000, the Bavarian State Office for the Environment (LfU) has been carrying out studies of the quality of Bavarian biowaste and green compost as well as fermentation residues from biowaste fermentation plants at intervals of several years (2002, 2006, 2009, 2013/14), and since 2009, in cooperation with the LfL, also of fermentation residues from agricultural biogas plants. In 2013/14, disease and phytosanitary parameters were also included in the study program.
The focus of the study is on investigations on a large number of organic pollutants that have so far hardly / not been determined in fermentation residues: polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), polychlorinated dibenzo-dioxins / furans (PCDD / F), dioxin-like PCBs, fungicides (Biphenyl, pentachlorophenol, ortho-phenylphenol, thiabendazole), hexachlorobenzene (HCB), plasticizers (phthalates) and raw materials for plastics (bisphenol A, iso-nonylphenol), organotin compounds, synthetic fragrances (galaxolides, tonalides), polybrominated flame retardants, per (PFT) and Triclosan (disinfectant).
The composts and fermentation residues did not differ significantly in terms of PAHs and the chlorinated pollutants PCDD / F, PCB and HCB. Almost all of the pollutants examined were also found in fermentation residues; the concentrations varied strongly in some cases. With the exception of PAH, the fermentation residues from biogas plants (NawaRo, co-fermentation) are significantly less contaminated than the composts. The NawaRo fermentation residues mostly had significantly lower pollutant contents (several times below the determination limit) than those from biowaste (co-) fermentation plants. The only organic pollutant that appeared in higher concentrations in the NawaRo fermentation residues was the fungicide pentachlorophenol (wood preservative). With regard to phyto-hygiene, all samples were harmless and complied with the requirements of the BioAbfV. The disease hygiene requirements of BioAbfV were met by all compost and digestate from agricultural biogas plants. Salmonella was detected in two (out of four) liquid biowaste fermentation residues.

Recycling of biogenic waste: residues, pollutant content and hygiene parameters (Bavarian State Office for the Environment (2016)