Pollution Index by Country

Data cited at: Numbeo-https://www.numbeo.com/pollution/rankings_by_country.jsp?title=2020
Pollution Index is an estimation of the overall pollution in the city. The biggest weight is given to air pollution, than to water pollution/accessibility, two main pollution factors. Small weight is given to other pollution types.
Pollution Exp Scale is using an exponential scale to show very high numbers for very polluted cities, and very low numbers for unpolluted cities. Therefore to calculate formula it uses the exponential function to calculate the index.

数据引自：Numbeo，具体来源链接为https://www.numbeo.com/pollution/rankings_by_country.jsp?title=2020。
污染指数（Pollution Index）用于估算城市整体污染水平。该指数以空气污染为最高权重因子，其次为水污染/污染可及性，此二者为两大主要污染影响因素，其余污染类型仅分配较小权重。
污染指数级标尺（Pollution Exp Scale）采用指数标尺设计逻辑，可为高污染城市呈现极高数值，为低污染城市呈现极低数值，其计算过程通过指数函数完成该指数的生成。