Health Concerns over Drugs in Manured Crops
US - Dolliver and co-workers at the University of Minnesota have measured the uptake by maize, lettuce and potatoes of sulphamethazine, an antibiotic used in animal production, which is passed into manure. Although the uptake of the drug by the plants was low, the researchers indicated 'potential human health concerns of consuming low levels of antibiotics from produce grown on manure-amended soils'.
8 January 2009
2 minute read
Dolliver and his colleagues writes that animal manure is applied to agricultural land as a means to provide crop nutrients. However, animal manure often contains antibiotics as a result of extensive therapeutic and subtherapeutic use in livestock production.
The objective of their study was to evaluate plant uptake of a sulfonamide-class antibiotic, sulfamethazine, in corn (Zea mays L.), lettuce (Lactuca sativa L.), and potato (Solanum tuberosum L.) grown in a manure-amended soil.
The treatments were 0, 50 and 100 µg sulfamethazine per mL manure applied at a rate of 56,000 L per hectare.
Results from the 45-day greenhouse experiment showed that sulfamethazine was taken up by all three crops, with concentrations in plant tissue ranging from 0.1 to 1.2 mg per kg dry weight. Sulfamethazine concentrations in plant tissue increased with corresponding increase of sulfamethazine in manure. Highest plant tissue concentrations were found in corn and lettuce, followed by potato.
Total accumulation of sulfamethazine in plant tissue after 45 days of growth was less than 0.1 per cent of the amount applied to soil in manure.
These results raise potential human health concerns of consuming low levels of antibiotics from produce grown on manure-amended soils, conclude the researchers.
Reference
Dolliver H., Kumar K. and Gupta S. Department of Soil, Water, and Climate, University of Minnesota, 1991 Upper Buford Circle, St. Paul, MN 55108, USA.
