Organic Food Safety

Food pathogens

Animal manure is widely used as a fertiliser in organic farming systems and there has been concern about the risk of contamination of organic crops with human pathogens from manure.

As part of the EU-QualityLowInputFood project, a group of NEFG scientists reviewed Hazard Analysis; Critical Control Point based Food Safety Assurance Systems for food borne pathogens and results were published in the Journal of Applied Microbiology.

see also Leifert et al. 2008
Risks from pathogens such as Salmonella, Yersinia, Campylobacter and Escherichia coli O157 have been identified as a particular concern for organic and ‘low input’ food production systems that rely on livestock manure as a nutrient source. Current data does not allow any solid conclusions to be drawn about the level of this risk, relative to conventional production systems.
This review describes six Risk Reduction Points (RRPs) where risks from enteric pathogens can be reduced in ready-to-eat vegetables. Changes can be made to animal husbandry practices (RRP1) to reduce inoculum levels in manure. Outdoor livestock management (RRP2) can be optimised to eliminate the risk of faecal material entering irrigation water. Manure storage and processing (RRP3), soil management practices (RRP4) and timing of manure application (RRP5), can be adjusted to reduce the survival of pathogens originating from manure. During irrigation (RRP6), pathogen risks can be reduced by choosing a clean water source and minimising the chances of faecal material splashing on to the crop.
Although preventive measures at these RRPs can minimize enteric pathogen risk, zero risk can never be obtained for raw ready-to-eat vegetables. Good food hygiene practices at home are essential to reduce the incidence of food-borne illnesses.

Glyphosate Herbicides

Glyphosate is an organophosphate herbicide widely used in conventional farming and in particular herbicide (e.g. round-up) resistant crops. There is increasing concern about negative effects of glyphosate on human health.

Based on a literature review supported by a group of UK charities, a group of scientists therefore reviewed the limitations of the European regulatory process and safety assessment of glyphosate based herbicides and results were published in the Journal of Environmental and Analytical Toxicology .

see also Antoniou et al. 2013
The publication of a study in 2010, showing that a glyphosate herbicide formulation and glyphosate alone caused malformations in the embryos of Xenopus laevis and chickens through disruption of the retinoic acid signalling pathway, caused scientific and regulatory controversy.
Debate centred on the effects of the production and consumption of genetically modified Roundup Ready soy, which is engineered to tolerate applications of glyphosate herbicide. The study, along with others indicating teratogenic and reproductive effects from glyphosate herbicide exposure, was rebutted by the German Federal Office for Consumer Protection and Food Safety, BVL, as well as in industry-sponsored papers. These rebuttals relied partly on unpublished industry-sponsored studies commissioned for regulatory purposes, which, it was claimed, showed that glyphosate is not a teratogen or reproductive toxin.
However, examination of the German authorities’ draft assessment report on the industry studies, which underlies glyphosate’s EU authorisation, revealed further evidence of glyphosate’s teratogenicity. Many of the malformations found were of the type defined in the scientific literature as associated with retinoic acid teratogenesis. Nevertheless, the German and EU authorities minimized these findings in their assessment and set a potentially unsafe acceptable daily intake (ADI) level for glyphosate. This paper reviews the evidence on the teratogenicity and reproductive toxicity of glyphosate herbicides and concludes that a new and transparent risk assessment needs to be conducted.
The new risk assessment must take into account all the data on the toxicity of glyphosate and its commercial formulations, including data generated by independent scientists and published in the peer-reviewed scientific literature, as well as the industry-sponsored studies.

see also Myers et al. 2016
The broad-spectrum herbicide glyphosate (common trade name "Roundup" ) was first sold to farmers in 1974. Since the late 1970s, the volume of glyphosate-based herbicides (GBHs) applied has increased approximately 100-fold. Further increases in the volume applied are likely due to more and higher rates of application in response to the widespread emergence of glyphosate-resistant weeds and new, pre-harvest, dessicant use patterns. GBHs were developed to replace or reduce reliance on herbicides causing well-documented problems associated with drift and crop damage, slipping efficacy, and human health risks. Initial industry toxicity testing suggested that GBHs posed relatively low risks to non-target species, including mammals, leading regulatory authorities worldwide to set high acceptable exposure limits. To accommodate changes in GBH use patterns associated with genetically engineered, herbicide-tolerant crops, regulators have dramatically increased tolerance levels in maize, oilseed (soybeans and canola), and alfalfa crops and related livestock feeds. Animal and epidemiology studies published in the last decade, however, point to the need for a fresh look at glyphosate toxicity. Furthermore, the World Health Organization's International Agency for Research on Cancer recently concluded that glyphosate is "probably carcinogenic to humans." In response to changing GBH use patterns and advances in scientific understanding of their potential hazards, we have produced a Statement of Concern drawing on emerging science relevant to the safety of GBHs. Our Statement of Concern considers current published literature describing GBH uses, mechanisms of action, toxicity in laboratory animals, and epidemiological studies. It also examines the derivation of current human safety standards. We conclude that: (1) GBHs are the most heavily applied herbicide in the world and usage continues to rise; (2) Worldwide, GBHs often contaminate drinking water sources, precipitation, and air, especially in agricultural regions; (3) The half-life of glyphosate in water and soil is longer than previously recognized; (4) Glyphosate and its metabolites are widely present in the global soybean supply; (5) Human exposures to GBHs are rising; (6) Glyphosate is now authoritatively classified as a probable human carcinogen; (7) Regulatory estimates of tolerable daily intakes for glyphosate in the United States and European Union are based on outdated science. We offer a series of recommendations related to the need for new investments in epidemiological studies, biomonitoring, and toxicology studies that draw on the principles of endocrinology to determine whether the effects of GBHs are due to endocrine disrupting activities. We suggest that common commercial formulations of GBHs should be prioritized for inclusion in government-led toxicology testing programs such as the U.S. National Toxicology Program, as well as for biomonitoring as conducted by the U.S. Centers for Disease Control and Prevention.