Degradation of Polymer Materials in the Environment and Its Impact on the Health of Experimental Animals: A Review

Abstract

The extensive use of polymeric materials has resulted in significant environmental pollution, prompting the need for a deeper understanding of their degradation processes and impacts. This review provides a comprehensive analysis of the degradation of polymeric materials in the environment and their impact on the health of experimental animals. It identifies common polymers, delineates their degradation pathways, and describes the resulting products under different environmental conditions. The review covers physical, chemical, and biological degradation mechanisms, highlighting the complex interplay of factors influencing these processes. Furthermore, it examines the health implications of degradation products, using experimental animals as proxies for assessing potential risks to human health. By synthesizing current research, the review focuses on studies related to small organisms (primarily rodents and invertebrates, supplemented by fish and mollusks) to explore the effects of polymer materials on living organisms and underscores the urgency of developing and implementing effective polymer waste management strategies. These strategies are crucial for mitigating the adverse environmental and health impacts of polymer degradation, thus promoting a more sustainable interaction between human activities and the natural environment.

Keywords: environmental pollution; experimental animal; polymeric degradation; toxicity.

Figure 4

The distribution of microplastics in different environmental compartments. (a) Soil, reprinted with permission from [110]. (b) Marine environment, reprinted with permission from [111]. (c) Freshwater system, reprinted with permission from [114]. (d) Cryospheric region, reprinted with permission from [117], 2022, Elsevier.

Figure 6

Organ-specific toxicity of PS-MPs on mice. (a) Liver toxicity, reprinted with permission from [139], 2024, Elsevier. (b) Kidney toxicity, reprinted with permission from [142], 2023, Elsevier.

Figure 1

Persistence of the degradation products from polyethylene, polypropylene, polyvinyl chloride, polycarbonate, and polylactic acid.

Figure 2

Schematic diagram of photocatalytic reaction mechanism in different environments, reprinted with permission from [76], 2023, Royal Society of Chemistry.

Figure 3

Process diagram of polymer degradation mechanism.

Figure 5

Summary of the routes, damaged systems, types of cytotoxicity, and influencing factors of human exposure to microplastics, reprinted with permission from [129], 2023, Elsevier.

Figure 7

Neurotoxicity caused by animal exposure to polymeric material degradation products. (a) Mice exhibited depression and anxiety, reprinted with permission from [148], 2023, Elsevier. (b) Bees showed learning ability and memory retention impairment, reprinted with permission from [149], 2024, Elsevier.

Figure 8

The toxicity of exposure to the microplastic environment to the reproductive system of males and females, reprinted with permission from [154], 2024, Elsevier.