Contaminated Manure Taints US Organic Produce

Reports that US ‘organic’ vegetable growers could be contaminating their produce with antibiotic-laden manure raises questions over the quality of the £40m of ‘organic’ produce imported into the UK from the US every year.

Certified organic farmers in the US are allowed to use raw manure from livestock regularly treated with antibiotics and drugs. Jennifer Rohn reports in Chemistry & Industry magazine that nearly 60% of US organics growers do just that. Plants grown using this manure can take antibiotics up into their edible parts.

A team from the University of Minnesota recently demonstrated that corn, cabbage and green onions grown on manure from pigs fed antibiotics have detectable levels of the drug chlortetracycline. And they think that hormones may be absorbed in the same way.

Although the UK Soil Association says that vegetables imported into the UK have to been fertilised under prescribed conditions, they do not know whether these precautions are sufficient to inactivate any antibiotics present in manure.