What are the characteristics of the impact of environmental pollution on human health?

Although there are many kinds of pollutants that affect people's health, they all have a common feature: (1) the object range is wide. Environmental pollution affects a large area, involving a large area and a large population. (2) Low dose and long term. The concentration of pollutants in environmental pollution is low, and the contacts live in the polluted environment for 24 hours instead of just working for 8 hours. (3) Diversity of actions. The types of pollutants in the environment are very complex, and they have many biological effects, so the harm caused by pollutants to human body has many effects, such as local and systemic, specific and non-specific, long-term harm and short-term effects. (4) Complexity of environmental factors. Environmental pollution is not a single factor, but often many factors act on human body at the same time. (5) Long-term research objectives. The purpose of environmental protection is to protect residents' health and prolong their life. We should not only study toxic or non-toxic, acute or chronic poisoning, but also consider its long-term harm.