Environmental factors in Parkinson’s disease: New insights into the molecular mechanisms

•Environmental factors are important risk factors for PD.•We summarized the toxic mechanisms that different environmental factors played.•PM2.5 can increase the risk of PD, but the molecular mechanisms remain to be elucidated. Parkinson’s disease is a chronic, progressive neurodegenerative disorder affecting 2–3% of the population ≥65 years. It has long been characterized by motor impairment, autonomic dysfunction, and psychological and cognitive changes. The pathological hallmarks are intracellular inclusions containing α-synuclein aggregates and the loss of dopaminergic neurons in the substantia nigra. Parkinson’s disease is thought to be caused by a combination of various pathogenic factors, including genetic factors, environmental factors, and lifestyles. Although much research has focused on the genetic causes of PD, environmental risk factors also play a crucial role in the development of the disease. Here, we summarize the environmental risk factors that may increase the occurrence of PD, as well as the underlying molecular mechanisms.