Abstract

Background:
The global increase in plastic production worldwide, with improper waste processing, led to the distribution of microplastic contamination in soil, water, and food products, which, in turn, increases human health risk through the consumption of animal products.

Aim:
This study was designed to evaluate microplastic contamination in Awassi sheep edible tissues in Nineveh governorate, Iraq, using the contamination factor (CF) and pollution load index (PLI) parameters.

Methods:
Eighty meat (muscle), liver, and intestine samples were collected from four cities in Nineveh governorate. Samples were stored at -20°C in (Hitachi chest freezer, HRCS11316MNW, China), digested with KOH for 8h at 60°C, and isolated by density separation in a NaCl/ZnCl₂ solution. Samples were then filtered and examined using stereomicroscopy to determine count, shape, and size, and were analyzed by FTIR spectroscopy for polymer identification. Contamination levels were evaluated using the contamination factor (CF) and pollution load index (PLI), while human exposure risk was determined by calculating the annual meat consumption rate.

Results:
The contamination rate was the highest in Badush city, with medium-sized particles reached 77.6, 65.6 and 72.5 items/g in the meat, liver and intestine respectively. These particles were mostly irregular in shape and were black and brown. FTIR analysis confirmed the presence of nylon and polyethylene as primary polymers. The contamination factor (CF) and pollution load index (PLI) were the highest in Badush city, with an exposure rate reaching 676.1 particles/g in meat, higher than Mosul (523.3), Tel Keif (464.1), and Al-Hamdaniya (425.9). The contamination with microplastics in the liver and intestine was also greater in Badush, which was 9.8 and 10 particles/g, respectively.

Conclusion:
Given the potential biological toxicity of medium-sized microplastic particles, an immediate mitigation response is necessary. The discovery of nylon and polyethylene in animal tissues highlights the significance of microplastic pollution as a new threat to livestock health and food security. The extensive use of plastics in agricultural practices and food packaging is the primary source of contamination here.

Key words: Awassi sheep; FTIR spectroscopy; Microplastic; Nylon; Public Health.