Risk assessment of endocrine disrupting compounds in selected food items sold in open markets in Zambia; a comparison of Kitwe, Kabwe and Lusaka
Date
2024
Authors
Miyanza, Foster
Journal Title
Journal ISSN
Volume Title
Publisher
The University of Zambia
Abstract
Endocrine disrupting compounds (EDCs) are receiving increased attention in the environment due to their link to lifestyles diseases like hypertension, heart disease, type 2 diabetes and some cancers. This research aimed at assessing the presence and quantities of heavy metals and organic EDCs in the selected raw food items sold on open markets in the two cities and one town in Zambia. Fifty samples including Kapenta, fish and vegetables were collected from major open markets of Kitwe, Kabwe and Lusaka. Quick Easy, Cheap, Efficient, Rugged and Safe (QuEChERS) sample extraction technique was optimised for extraction of selected organic EDCs, with primary secondary amine (PSA) as clean-up sorbents. Microwave assisted digestion was used to extract
metals. Optimised QuEChERS parameters used are 75 mg clean-up sorbent, 5 min extraction time, 400 rpm separation speed, 0.5 g salt (NaCl), 6 mL methanol as extraction solvent. Detection was done using gas chromatography-mass spectrometry and inductively coupled plasma-optic emission spectroscopy for organic EDCs and heavy metals, respectively. The results showed that
DDT metabolites, including 4-nonylphenol, were not detected in all the foodstuffs. The mean concentrations of dimethyl phthalate (DMP) ranged from 91.05 to 101.76 μg/kg, 77.14 to 123.82
μg/kg, and 85.65 to 98.55 μg/kg for samples from Kitwe, Kabwe and Lusaka, respectively. The mean concentrations of diethyl phthalate (DEP) ranged from 21.46 to 80.69 μg/kg, 63.93 to 161.67
μg/kg and 23.22 to 46.01 μg/kg for samples from Kitwe, Kabwe and Lusaka, respectively. There was no significant difference in the mean concentrations of DMP in all the samples from markets
Kabwe, Kitwe and Lusaka, P>0.05. The mean concentrations of DEP showed no significant difference for samples from Kitwe and Lusaka, P>0.05. However, a significant difference,
P>0.0167, in the mean concentrations was found between samples from Kitwe and Kabwe, and samples from Kabwe and Lusaka with samples from Kabwe Town having higher concentrations,
upto 123.82 μg/kg compared to 101.76 μg/kg and 98.55 μg/kg, in both cases. The health risk analysis of DMP and DEP recorded the hazard index that is less than one, which indicates that the
consumers are safe from the health effects that result from exposure to these phthalates through consumption of food. The investigation revealed that the mean level of trace elements ranged: Cd 3.0±0.33 to Al 3472.3±25 mg/kg for Kitwe; Cd 2.0±0.67 to Al 1698.7±17 mg/kg for Lusaka; Cd 1.9±0.31 to Al 662.7±6.01 mg/kg for Kabwe. The Hazard Index (HI) for all metals in all samples from all markets in Kabwe, Kitwe and Lusaka were greater than 1 indicating possible noncarcinogenic risk. The Carcinogenic Risk (CR) for cadmium was higher than 10-4 in all samples
from all markets in Kabwe, Kitwe and Lusaka. This indicates possible carcinogenic risk from prolonged consumption of foods under study. However, it is recommended that further studies
need to be done to assess total phthalate exposure in order to make wholesome conclusions with regards to health risk through consumption of food from open markets.
Description
Thesis of Master of Science in Integrated Water Resources Management