Document Type

Thesis

Date of Award

5-2023

School/College

College of Science, Engineering, and Technology (COSET)

Degree Name

MS in Biology

Committee Chairperson

Ayodotun Sodipe

Committee Member 1

Sonya Good

Committee Member 2

Audrey Player

Committee Member 3

Shirshi Shishodia

Keywords

• Bio-accumulation • Detoxification • Global contamination • Heavy metals • Metalloids • Toxicity

Abstract

Heavy metals and metalloids such as lead, cadmium, arsenic, nickel and zinc are an unavoidable contaminant of our ecosystem because of its natural occurrence They are also introduced into the environment anthropogenically through manufacturing, industrial agricultural processes which contaminates the food chain when taken up by food producing crops as a result of their presence in soil and water used in planting or feeding livestock. The adverse effects of these toxic elements have become a global threat to food security, particularly due to their inextricable association with human health. Exposure to environmental contaminants from daily diet is a major concern for all ages, although children are more vulnerable to their effects because they consume more food relative to their body weight and have underdeveloped nervous system. Exposure to toxic metals in children presents long-term health risks to growing infants and toddlers and have been linked but not limited to a variety of health issues such as disruptive behavior, neurological damage and attention deficit hyperactivity. A report recently released by the U.S House of Representatives in 2021, raised concerns about the dangerously elevated levels of heavy metals in baby food due to improper testing of raw ingredients used in making baby foods and finished baby food products and under-reporting by food manufacturers, of these high levels of toxicity which keeps toxic products on the market. Although, heavy metals can be found in some foods due to contaminated water and soil, their levels in foods, especially baby foods should be of great concern. The U.S. Food and Drug Administration (FDA) has proposed daily permissible limits for some of these metals; however, a major challenge to this remains subpar testing practices, lenient self-regulating standards set by different food manufacturers where there are inconsistent and conflicting tolerable safe limit values set by various food agencies. The new U.S. FDA initiative, known as Closer to Zero Plan (C2Z) seeks to reduce to almost zero level, the toxic element exposures from foods eaten by babies and young children, therefore, this study was aimed at evaluating heavy metal concentrations in baby and toddler food products targeted at infant and toddler age groups produced by leading brands indicated in the report. Ten commercial baby foods from the top seven leading brands in the United States were purchased from a local store, representing six ingredient categories listed as a diary, fruit; leguminous vegetable; beef, chicken, root vegetable; or grains and evaluated for arsenic (As), cadmium (Cd), Zinc (Zn) lead (Pb), Nickel (Ni), aluminum (Al) and chromium (Cr) in triplicates for heavy metal concentrations using the triple quadrupole inductively coupled mass spectrometry ) QQQ_ICP-MS), a tandem mass spectrometer method that has the capability of detecting analytes at lower detection limits. Nickel, Chromium and Zinc are vital in living organisms and necessary for metabolic and immune support while Arsenic, and Lead are non-essential but can be highly toxic even at extremely low concentrations of 0.005ug/g. In all the food types evaluated, aluminum (4.09 µg/g and 2.50 µg/g) and zinc (33.5 µg/g 69.5 µg/g, and 30.2 µg/g) were the most elevated in the infant food age group while lead and cadmium metals in all other food types were observed at levels not exceeding the tolerable limits except in rice cereal. The acceptable daily limits of Aluminum and Zinc are 1 µg/g /day and 0.3 µg/g /day. The mixed model generated for this analysis found significant differences in metal concentrations (F6,24=2.75, p=0.03). The overall average metal concentration in the food was 0.96 µg/g. No significant correlations were found between the packaging materials used and the observed metal concentrations (P >0.05, Std error 1.94). Food products formulated from fruits and root tubers commonly referred to as plant-based food products, exhibited the highest concentrations of all tested heavy metals although none of the food labels reported the levels of heavy metal concentrations in the food products. Transparency in reporting toxic metal content on food labels will help consumers make an informed decision when purchasing these food products.

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