Source: MICHIGAN STATE UNIV submitted to
HOW FOOD CROPS BECOME CONTAMINATED WITH HEAVY METALS: MULTIVARIABLE ANALYSIS IN CLIMATE AND FIELD CONDITIONS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1030551
Grant No.
2023-67017-40049
Cumulative Award Amt.
$610,996.00
Proposal No.
2022-09010
Multistate No.
(N/A)
Project Start Date
Aug 1, 2023
Project End Date
Jul 31, 2026
Grant Year
2023
Program Code
[A1332]- Food Safety and Defense
Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824
Performing Department
Plant, Soil and Microbial Sciences
Non Technical Summary
Heavy metal contamination of food, particularly infant food, is a significant food safety risk in the United States. Crop uptake of heavy metals are very variable and difficult to predict, due to multiple soil, field, climate, and plant factors, posing great challenge to minimizing heavy metals in food crops. In this project researchers from Michigan State University will examine multiple factors such as soil properties (e.g., soil wetting-drying patterns), field topography, climate, and crop traits that contribute to heavy metal contamination of food crops. This project will assess if field topography and soil wetting-drying cycles are major determinants for mobilization of heavy metals to soil pore water and subsequent crop contamination.Specifically, this project will investigate the mobilization of heavy metals (As, Cd, and Pb) and their uptake by food crops (carrot and wheat) at various growth stages under archetypical soil wetting-drying periods in well-controlled greenhouse microcosms. Then the spatiotemporal variability of crop uptake of heavy metals (As, Cd, and Pb) across carrot and wheat fields will be studied. Finally, multivariable plant uptake, exposure, and risk models and management guidelines will be developed for mitigating heavy metal accumulation in food crops. This project will generate fundamental knowledge on factors controlling crop uptake of heavy metals in agricultural fields and develop practical tools for farmers to mitigate the contamination of food crops by heavy metals, thus contributing to the safety and sustainability of US agriculture and public health.
Animal Health Component
30%
Research Effort Categories
Basic
50%
Applied
30%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1040110200010%
7111599200010%
7111599201010%
7111599102010%
7111499200010%
7111499201010%
7111499102010%
1331599200010%
1331499200010%
7235010117010%
Knowledge Area
711 - Ensure Food Products Free of Harmful Chemicals, Including Residues from Agricultural and Other Sources; 133 - Pollution Prevention and Mitigation; 104 - Protect Soil from Harmful Effects of Natural Elements; 723 - Hazards to Human Health and Safety;

Subject Of Investigation
1499 - Vegetables, general/other; 0110 - Soil; 1599 - Grain crops, general/other; 5010 - Food;

Field Of Science
2010 - Physics; 2000 - Chemistry; 1020 - Physiology; 1170 - Epidemiology;
Goals / Objectives
The major goal of this project is to elucidatemultiplefactors such as soil properties (e.g., soil wetting-drying patterns), field topography, climate, and crop traits responsible for contamination of food crops by heavy metals (As, Cd, and Pb). We hypothesize that field topography and soil wetting-drying cycles are major determinants for mobilization of heavy metals to soil pore water and subsequent crop contamination. This project has three objectives:1) Investigate the mobilization of heavy metals (As, Cd, and Pb) and their uptake by food crops (carrot and wheat) at various growth stages under archetypical soil wetting-drying periods in well-controlled greenhouse microcosms;2) Study the spatiotemporal variability of crop uptake of heavy metals (As, Cd, and Pb) across carrot and wheat fields;3) Develop multivariable plant uptake, exposure, and risk models and management guidelines for mitigating heavy metal accumulation in food crops.
Project Methods
A combination of laboratory, field, and computational approaches will be used to elucidate multiple factors controlling mobilization and uptake of heavy metals in agricultural crops (carrot and wheat). In Objective 1 archetypical soil water conditions (i.e., alternating wetting-drying periods) will be simulated in well-controlled microcosms packed with field-collected soils. The mobilization of heavy metals to soil pore water, plant growth, and the uptake and accumulation of heavy metals in plants will be quantified, which will allow for investigating the interactions of plants and soils in terms of heavy metal mobilization and uptake. In Objective 2 field studies (carrot and wheat) will be carried out with in-situ real-time monitoring of soil water content, fine-grid soil sampling, and time-resolved sampling of soil pore water and plants across topographical positions (summit, midslope, and toeslope) of the fields. Meteorological parameters such as precipitation, wind speed, and air temperature will be measured by on-site weather stations. The field studies aim to identify field factors responsible for enhanced uptake and accumulation of heavy metals by food crops. Finally, in Objective 3 based on what we learn from the laboratory and field studies, we will develop machine learning models to predict heavy metal concentrations in crop plants across a field by using field soil, plant, and climatic data. Then a field-scale heavy metal exposure model will be developed to quantify the spatially-resolved metal exposure and health risk at the field scale. Finally, we will produce a guideline of management practices for mitigation of heavy metals in food crops by combining risk factors studied in Objectives 1 and 2 with results of other ongoing studies and the literature.The outcome of this project will mainly be evaluated by the quality and number of referred journal publications and conference presentations, and the academic progress and achievement of graduate students supported by this project. The evaluation surveys of the outreach events such as Science Festival, Annual Ag Expo, Agriculture Innovation Day, and annual Extension field days at Michigan State Universitywill be performed.

Progress 08/01/23 to 07/31/24

Outputs
Target Audience:The primary target audience will be the scientific community and extension professionals in the fields of soil and water science, food science, food safety, crop science, environmental health science, etc. This research will benefit farming communities because the improved knowledge on factors responsible for crop contamination with heavy metals and development of predictive models on crop metal uptake and resultant human exposure will help growers produce safe food crops. This project will also help food processors to source food crops of highest quality. This project will be of interest to policy makers and the public who are keen to protecting food quality and the public health. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project provided the support for four graduate students (half-time graduate research assistantship) and one postdoc. Their research results were presented in the international and national meetings (such as the ASA-CSSA-SSSA International Annual Meeting and the Society for Risk Analysis Annual Meeting). The PD's attendance at the annual USDA PD meeting was supported by the project. How have the results been disseminated to communities of interest?The results have been presented in three scientific meetings including nine conference presentations. Two manuscripts were published. The research output has increased the impact of our project. What do you plan to do during the next reporting period to accomplish the goals?Next year, we will continue to investigate the effect of soil water conditions on the uptake and accumulation of metal(loid)s in wheat grown in greenhouse. We will continue the field trials with soil amendments and field slope. The second-year slope and amendment trials for winter wheat were established in October 2024, and the site-selection for 2025 carrot trials will take place late winter/early spring in collaboration with Gerber and growers. We will start developing the crop uptake and exposure models for toxic metal(loid)s.

Impacts
What was accomplished under these goals? In Year 1 of the project, we started investigating the effect of soil wetting-drying conditions on the uptake of heavy metals by carrots (Daucus carota) in a greenhouse growth experiment. The carrots were grown in a sandy soil over five growth stages to maturity (up to 107 days) under three wetting-drying regimes. The five stages of carrot growth were organized into three phases and each phase was maintained at either 35% or 80% of soil water holding capacity (i.e., dry period or wet period) to assess the carrot growth and the uptake of heavy metals, resulting in three treatments, i.e., DDW (dry-dry-wet), WDD (wet-dry-dry), and WWW (wet-wet-wet). At the end of each growth stage, the carrot lateral root, storage root, shoot, bulk soil, and rhizosphere soil samples were collected for each treatment with triplicates. The samples were acid-digested with the microwave digestion method and analyzed by inductively coupled plasma - mass spectrometry for metal concentrations. The data were analyzed to determine the concentrations of heavy metals in the root and shoot samples, the root concentration factors (RCF), and root-to-shoot translocation factors (TF) among various wetting-drying treatments. The wetting-drying conditions influenced the metal uptake by carrots. The storage root growth was slower under dry conditions, and the targeted metal concentrations decreased over time. TFs for Pb, Cd, and As increased, whereas RCFs declined. The use of ICP-MS also allowed for inclusion of a suite of other metal(loid)s including both toxic and essential elements to humans, which is being used for analyzing metallomes and the composition difference of metallomes in carrot roots and shoots under various treatments. This approach is advantageous in its ability to evaluate the impact of soil water conditions on the uptake and accumulation of all metal(loid)s in carrots. We completed a three-month greenhouse study to study the uptake of heavy metals by carrots in a sandy soil at 65% water holding capacity, as influenced by soil amendments (0.3% w/w) including biochar, gypsum, and zeolite as single amendment, three 1:1 mixtures of biochar-gypsum, biochar-zeolite, and gypsum-zeolite, and one 1:1:1 mixture of the above three amendments. Wood ash, with high toxic metal(loid)s concentration, was included as positive control. Concentrations of metal(loid)s in the carrot root, shoot, bulk soil, and rhizosphere soil samples were measured and RCFs, and TFs of the metal(loid)s were analyzed. Metallome "community" analysis was conducted to assess any effect of various soil amendments on the toxic metallome in carrots. All field work and laboratory analysis for the four summer 2024 field trials have been completed. The completed experiments include the soil amendment trial in winter wheat at MSU campus Agronomy Farm, the slope trial in winter wheat at Clarksville Research Station, the on-farm soil amendment trial in carrots, and the on-farm slope trial in carrots (both in Oceana County). The second year slope and amendment trials for winter wheat were established in October 2024, and the site-selection for 2025 carrot trials will take place late winter/early spring in collaboration with Gerber and growers. We have also carried out the outreach/engagement activities, including eight total project calls with Gerber staff and leadership in 2024, two combined calls with Gerber and colleagues from Louisiana State University (LSU) and Purdue University working on heavy metals to develop future collaborations, and meeting/discussion on heavy metal challenge with Michigan Carrot Committee Board. We also performed the exposure and health risk assessment via dietary exposure to toxic metals and evaluated the effect of agricultural practices on the metal exposure.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gamlath, C., F. Wu, and P. Hsu. Estimation of a toxicological reference value for dietary arsenic exposure based on cardiovascular disease risk. Society for Risk Analysis Annual Meeting, Austin, TX, December 8-12, 2024.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Scott, C. and F. Wu. Analysis of Potential Elevated Inorganic Arsenic Content in Brown Rice Compared to White Rice. Society for Risk Analysis Annual Meeting, Austin, TX, December 8-12, 2024.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Hsu, P., F. Wu, and C. Scott. Quantifying the Burden of Dietary Lead Exposure on Childhood Cognitive and Behavioral Disorders in the US: A DALY Calculation. Society for Risk Analysis Annual Meeting, Austin, TX, December 8-12, 2024.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Scott CK, Wu F (2024). Unintended food safety impacts of the agricultural circular economy: Case studies in arsenic and mycotoxins. NPJ-Science of Food, DOI: 10.1038/s41538-024-00293-8.
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Pokharel A, Wu F (2023). Dietary exposure to cadmium from rice, spinach, and common cereal grains among infants and young children in the United States. Food & Chemical Toxicology 178:113873. https://doi.org/10.1016/j.fct.2023.113873
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Wu, F., P. Hsu, C. Gamlath, C. Scott, and R. Rahman. 2024. FDA's New Action Levels for Toxic Elements: Public Health vs. Economic Impacts, and Solutions. Society for Risk Analysis Annual Meeting, Austin, TX, December 8-12, 2024.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Bearss, M.K.L.S., Z.D. Hayden, and K.S. Steinke. 2024. Mitigating uptake and bioavailability of heavy metals in winter wheat and carrot. ASA-CSSA-SSSA Annual Meeting. San Antonio, TX. November 10-13. (Poster)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Steinke, K.S., Z.D. Hayden, and M.K.L.S. Bearrs. 2024. Is Field Crop Contamination with Heavy Metals an Emerging Concern? North Central Soil Fertility Conference. Des Moines, IA. November 20-21. (Oral with proceedings)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Zhang, W. (2024) Environmental Contaminants in Soil, Water, and Plant Systems [Abstract]. ASA, CSSA, SSSA International Annual Meeting, San Antonio, TX. https://scisoc.confex.com/scisoc/2024am/meetingapp.cgi/Paper/159048
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Cao, Q., Li, C., Hayden, Z. D., Steinke, K., Li, H., & Zhang, W. (2024) Effects of Soil Water Conditions on Heavy Metal Uptake in Carrots [Abstract]. ASA, CSSA, SSSA International Annual Meeting, San Antonio, TX. https://scisoc.confex.com/scisoc/2024am/meetingapp.cgi/Paper/159166
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Li, C., Cao, Q., Ellis, K., Li, H., Steinke, K., Hayden, Z. D., & Zhang, W. (2024) How Do Soil Amendments Influence Toxic Metallome of Carrots? [Abstract]. ASA, CSSA, SSSA International Annual Meeting, San Antonio, TX. https://scisoc.confex.com/scisoc/2024am/meetingapp.cgi/Paper/160103