Announcements: The 49^thWorld Environment Day — June 5, 2020

World Environment Day, established by the United Nations (UN) at the first Conference on the Human Environment in 1972, is designated each year on June 5 to forge a basic common outlook on how to address the challenge of preserving and enhancing the human environment. World Environment Day is one of the principal vehicles through which the UN stimulates worldwide awareness of the environment and enhances political attention and action, and it is now the most renowned day for environmental action with more than 100 countries joining.

The Ministry of Ecology and Environment announced the theme for the 2020 World Environment Day — “Act towards a Beautiful China”, intending to encourage all citizens of the general public to actively contribute to the building of a civilization focused on ecological protection through working together to prevent and control pollution and to develop a beautiful country with blue skies, green lands, and clean waters (1).

In the last several decades, environmental pollution has become increasingly prominent in China with several key aspects such as the atmosphere (urban pollution, greenhouse gases, etc.), land (desertification, chemical pollution, etc.), water (pollution including antibiotics/nanopollutants, etc.), oceans (plastic waste, polar melting, etc.), and biodiversity (extinction of genes, species, and ecosystems, etc.). The environmental factors related to health impact have become a significant public health concern in China (2). Revised environmental protection law (2015), Healthy China 2030 etc. address the importance of enhancing environmental monitoring, health surveillance, and risk assessment system in the environmental health activities. These policies also stress the importance of carrying out work on environmental health for protecting public health.

In this issue, we invited colleagues from National Institute of Environmental Health, China CDC, Chinese Research Academy of Environmental Sciences, and Fudan University to report their latest research findings on environmental health. Liu et al. assessed the air quality after the implementation of the Clean Air Action in Beijing-Tianjin-Hebei, China. They found significant improvements in air quality and also explored the evolution of air pollution characteristics. Zhong et al. reported the association between high temperature and non-accidental and circulatory mortality in 130 Chinese counties from 2013 to 2018 and found that the daily mean temperature was the optimal indicator for high temperature related mortality risk assessment. Lyu et al. investigated the antibiotics in drinking water and reported the health risks in 6 large river basins, inland river areas, and key lake and reservoir areas of China in 2017, which revealed the potential antibiotic threats for public health in China. Fan et al. conducted a baseline investigation on residential PM_2.5pollution in 12 cities in China in 2018 and suggested the necessity for controlling the residential PM_2.5pollution in China. Niu et al. found the positive association between short-term exposure to ambient ozone and outpatient visits for respiratory diseases in 5 cities in China, which may further guide policy-making for reducing ozone air pollution and improving public health. We hope these studies in this special issue may encourage readers to better understand environmental and health issues and provide public health policy implications for future environmental health policy-making in China.