Occurrence of microplastic, antibiotics, hormones, and heavy metals in livestock and poultry manure in west iran

Identifying emerging contaminants in animal manure has great importance in sustainable development. Therefore, in this study, microplastics, antibiotics, hormones, and heavy metals in cow (COM) and poultry manure (POM) were investigated in Kermanshah province, which is one of the hubs of livestock and poultry farming. A total of 71.42% of the samples contained microplastics with four morphotypes: fiber, film, fragment, and sphere. These microplastics were characterized by colorless, green, yellow, blue, white, and black hues. PE and PP were the maximum composition. The abundance and diversity of microplastics in COM were higher than in POM. The concentration of doxycycline, erythromycin, enrofloxacin, and progesterone was in the range of 0.53-2.3 mg/kg, 0.49-1.9 mg/kg, 0.54-2.6 mg/kg, and 46.2-21.5 mg/kg, respectively. Zn (mg/kg) in COM and POM was 248.16 ± 31.62 and 200.1 ± 39.17, respectively, which were the maximum heavy metals. The average of Cr and Cu in COM was recorded as 34.46 ± 17.58 and 100.2 ± 2.22.03, and in POM as 34.2 ± 11.6 and 148.4 ± 57.02, respectively. The direct application of COM and POM could be a new route for the presence of emerging pollutants in agricultural soils. Therefore, this issue should be given serious attention by the environmental officials in Iran, and a solution should be devised.