Sustainable Food Production Practices May Pose Food Safety Dilemmas

Newswise — Washington D.C. -- When the agricultural “circular economy” is discussed in the context of sustainable food production, it is important to consider both food safety and food quality impacts. While sustainable methods are often aimed at reducing water and chemical inputs, carbon emissions, and fuel and labor costs, unintended food safety effects should also be considered going forward.

A new study on food crop production finds that alternative cultivation practices that reduce water use may reduce greenhouse gas emissions and arsenic concentrations in rice crops — a potential health threat — but may unfortunately also boost levels of cadmium in rice plants. In another portion of the study, no-till practices were found to boost the likelihood that mycotoxins will contaminate the next season’s crops, causing potential human and animal health risks. The paper appears in a recent issue of the peer-reviewed journal Science of Food. The paper was supported by IAFNS Food & Chemical Safety Committee. 

Part I: Metals and Alternative Irrigation in Rice Crops 

Alternative cultivation practices are often discussed as environmentally sound approaches that don’t affect other parts of the food cycle. But new research suggests food safety concerns should be taken seriously before new practices are adopted.

For example, continually flooded rice paddy production (the traditional method of producing rice) boosts arsenic concentrations in rice. But alternate wetting-drying rice production methods, which allow rice paddies to dry before rewetting, saves water, reduces costs to growers, and reduces the risk of arsenic uptake from soil. Dryer soils may lead to greater uptake of cadmium in crop plants, however.

According to co-authors Christian Kelly Scott and Felicia Wu of Michigan State University, “This is far from an ideal solution, with increased exposure to cadmium even as arsenic decreases in alternate wetting-drying rice production. From a human health perspective, we must compare the amounts of arsenic and cadmium that would be taken up in each scenario and consider their relative toxicities.”

The authors remind readers that alternative cultivation practices are not all-or-nothing strategies, and rice farmers often carefully weigh the specific amount of flooding and dry field management in a manner that optimally reduces both arsenic and cadmium uptake by their crops. 

Part II: Mycotoxins Under ‘No-Till’ Management

Tilling, or turning over the soil in an agriculture field, generally happens after harvest or before planting to remove crop residues and/or weeds. But some farmers opt for “no-till” practices or leaving crop residues on farmland after harvesting, to protect soil nutrients and prevent soil erosion.

However, it has been shown that pathogens may survive more efficiently and colonize the following season’s crops under no-till conditions. If fungi persist, they may produce mycotoxins which can contribute to cancer, immunosuppression, and growth impairment in humans and harm animals.

If the agricultural products that farmers produce exceed the limits of consumable mycotoxins, they cannot be sold for human or animal consumption due to regulations on allowable mycotoxin levels in over 100 nations worldwide.

Because the aforementioned mycotoxins can cause a diversity of serious health effects, this food safety issue must be taken into account when considering the benefits and costs of adopting no-till farming practices. 

The promise of sustainable agriculture warrants more discussion and debate and as techniques are refined, new research should highlight unintended consequences so adjustments can continue to be made. This paper highlights several food safety outcomes stemming from alternative practices that merit closer attention and focus.

According to senior author Felicia Wu, “Sustainable agriculture and agricultural circular economies provide many benefits for the environment. However, food safety and human health impacts must also be taken into account when adopting such practices.” 

The paper is available here.

The Institute for the Advancement of Food and Nutrition Sciences (IAFNS) is committed to leading positive change across the food and beverage ecosystem. This paper was supported in part by IAFNS Food & Chemical Safety Committee. IAFNS is a 501(c)(3) science-focused nonprofit uniquely positioned to mobilize government, industry and academia to drive, fund and lead actionable research. iafns.org