Impact of Microplastics and Nanoplastics on Livestock Health: An Emerging Risk for Reproductive Efficiency

Abstract

Pollution due to microplastics and nanoplastics is one of the major environmental issues of the last decade and represents a growing threat to human and animal health. In aquatic species, there is a large amount of information regarding the perturbation of marine organisms; instead, there are only a few studies focusing on the pathophysiological consequences of an acute and chronic exposure to micro- and nanoplastics in mammalian systems, especially on the reproductive system. There are several studies that have described the damage caused by plastic particles, including oxidative stress, apoptosis, inflammatory response, dysregulation of the endocrine system and accumulation in various organs. In addition to this, microplastics have recently been found to influence the evolution of microbial communities and increase the gene exchange, including antibiotic and metal resistance genes. Special attention must be paid to farm animals, because they produce food such as milk, eggs and meat, with the consequent risk of biological amplification along the food chain. The results of several studies indicate that there is an accumulation of microplastics and nanoplastics in human and animal tissues, with several negative effects, but all the effects in the body have not been ascertained, especially considering the long-term consequences. This review provides an overview of the possible adverse effects of the exposure of livestock to micro- and nanoplastics and assesses the potential risks for the disruption of reproductive physiological functions.

Keywords: BPA; bovine; cattle; cow; granulosa cells; health; microplastics; nanoplastics; reproductive system; steroid hormone.

Figure 1

A schematic diagram of the sources and fate of plastic particles in the soil. Silage covers, strings of the attached when baling hay, irrigation with water contaminated by MPs, plastic mulch, sludge and fertilizers, municipal waste degradation, tire abrasion and roadside litter affect the structure, fertility, nutrients and microbes of the soil. Land is used to produce feed for food-producing animals, which can be consumed fresh or stored. All of these sources increase the risk to human health through the ingestion of MPs from milk, meat and eggs.

Figure 2

Risks, effects and consequences of MPs/NPs on reproduction.