Aflatoxin Regulations in a Network of Global Maize Trade

Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000-2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B1, B2, G1, and G2) differ by more than 5 μg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards. © 2012 Wu, Guclu

Climate Change and Aflatoxin in Corn

The possible impacts of climate change on field crop production are many; however, most attention to date has been paid to projecting locational effects on yield and commercial viability (e.g., Zhao et al. 2017). But an altered climate will also have more nuanced effects through impacts on grain composition, safety, and quality. Our interest here is in how changing summertime weather patterns in the US central Corn Belt can provide an opening for increased aflatoxin damage in corn

A Mathematical Model for Pathogen Cross-Contamination Dynamics During Produce Wash

One of the main challenges for the fresh-food produce industry is to ensure that the produce is free from harmful pathogens. A potential area of risk is due to cross-contamination in a sanitizing chlorine wash-cycle, where the same water is used to wash contaminated as well as non-contaminated produce. However, this is also an area where effective intervention strategies are possible, provided we have a good understanding of the mechanism of cross-contamination. Based on recent experimental work by Luo, Y. et al. A pilot plant scale evaluation of a new process aid for enhancing chlorine efficacy against pathogen survival and cross-contamination during produce wash, International Journal of Food Microbiology, 158 (2012), 133–139, we have built mathematical models that allow us to quantify the amount of cross-contamination of Escherichia coli O157:H7 from spinach to lettuce, and assessed the efficacy of the associated wash-cycle protocols

Bt corn and cotton planting may benefit peanut growers by reducing aflatoxin risk

Decades of studies have shown that Bt corn, by reducing insect damage, has lower levels of mycotoxins (fungal toxins), such as aflatoxin and fumonisin, than conventional corn. We used crop insurance data to infer that this benefit from Bt crops extends to reducing aflatoxin risk in peanuts: a non-Bt crop. In consequence, we suggest that any benefit–cost assessment of how transgenic Bt crops affect food safety should not be limited to assessing those crops alone; because the insect pest control offered by Bt crops affects the food safety profile of other crops grown nearby. Specifically, we found that higher Bt corn and Bt cotton planting rates in peanut-growing areas of the United States were associated with lower aflatoxin risk in peanuts as measured by aflatoxin-related insurance claims filed by peanut growers. Drought-related insurance claims were also lower: possibly due to Bt crops' suppression of insects that would otherwise feed on roots, rendering peanut plants more vulnerable to drought. These findings have implications for countries worldwide where policies allow Bt cotton but not Bt food crops to be grown: simply planting a Bt crop may reduce aflatoxin and drought stress in nearby food crops, resulting in a safer food supply through an inter-crop “halo effect.”This article is published as Yu, J., Hennessy, D.A. and Wu, F. (2024) Bt corn and cotton planting may benefit peanut growers by reducing aflatoxin risk. Plant Biotechnol. J., https://doi.org/10.1111/pbi.14425. © 2024 The Author(s). This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made

Self-assembly of magnetic iron oxide nanoparticles into cuboidal superstructures

This chapter describes the synthesis and some characteristics of magnetic iron oxide nanoparticles, mainly nanocubes, and focus on their self-assembly into crystalline cuboids in dispersion. The influence of external magnetic fields, the concentration of particles, and the temperature on the assembly process is experimentally investigated

Climate change will increase aflatoxin presence in US Corn

The impacts of climate change on agricultural production are a global concern and have already begun to occur (Kawasaki 2018 Am. J. Agric. Econ. 101 172–92; Ortiz-Bobea et al 2021 Nat. Clim. Change 11 306–12), with major drivers including warmer temperatures and the occurrence of extreme weather events (Lobell and Field 2007 Environ. Res. Lett. 2 014002; Challinor et al 2014 Nat. Clim. Change 4 287; Rosenzweig et al 2001 Glob. Change Hum. Health 2 90–104; Schlenker and Roberts 2009 Proc. Natl Acad. Sci. USA 106 15594–8; Lobell et al 2014 Science 344 516–9; Ortiz-Bobea et al 2019 Environ. Res. Lett. 14 064003). An important dimension of the climate change-crop yield relationship that has often been overlooked in the empirical literature is the influence that warming temperatures can have on plant damage arriving through biotic channels, such as pest infestation or fungal infection (Rosenzweig et al 2001 Glob. Change Hum. Health 2 90–104). Aflatoxins are carcinogenic chemicals produced by the fungi Aspergillus flavus and A. parasiticus, which commonly infect food crops. Currently, in the United States, aflatoxin is a perennial contaminant in corn grown in the South, but rare in the Corn Belt and northern states. Climate change may expand aflatoxin's geographical prevalence, however; because hot, dry summers promote aflatoxin accumulation. Here we model aflatoxin risk as a function of corn plant growth stages and weather to predict US regions with high aflatoxin risk in 2031–2040, based on 16 climate change models. Our results suggest that over 89.5% of corn-growing counties in 15 states, including the Corn Belt, will experience increased aflatoxin contamination in 2031–2040 compared to 2011–2020. Interestingly, the results are spatially heterogeneous and include several southern counties expected to have lower aflatoxin risk, because the causative fungi become inactivated at very high temperatures.This article is published as Yu, Jina, David A. Hennessy, Jesse Tack, and Felicia Wu. "Climate change will increase aflatoxin presence in US Corn." Environmental Research Letters 17, no. 5 (2022): 054017. doi:10.1088/1748-9326/ac6435. © 2022 The Author(s). Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI

In Search of a Common European Approach to a Healthy Indoor Environment

Increasingly, policymakers in Europe and around the world are realizing the importance of healthy indoor environments for public health. Certain member states of the European Union (EU) have already achieved successes in improving indoor environmental quality, such as controlling certain contaminants (e.g., environmental tobacco smoke) or developing nationwide policies that address indoor air generally. However, a common European approach to achieving healthy indoor environments is desirable for several reasons including providing a broader recognition of the problem of unhealthy indoor air, setting a policy example for all 27 EU member states, and achieving greater public health equity across the different European nations. In this article we address the question “Why is it so difficult in the EU to develop a coherent approach on indoor environment?” We identify and describe four main barriers: a) the subsidiarity principle in EU policymaking, introducing decentralization of decision making to the member states; b) fragmentation of the topic of the indoor environment; c) the differences in climate and governance among different member states that make a common policy difficult; and d) economic issues. We discuss potential lessons and recommendations from EU and U.S. successes in achieving healthier indoor environments through various policy mechanisms