Environment Counts | WHO links 23% of global deaths to the environment :

The World Health Organization (WHO) has released statistics linking 23% of global deaths or roughly 12.6 million deaths a year to the environment.
The most common causes of death linked to the environment are stroke, ischaemic heart disease, unintentional injuries (accidents and natural disasters), cancers, and chronic respiratory diseases.
8.2 million of the 12.6 million deaths are due to noncommunicable diseases (heart disease, unintentional injuries, cancers, respiratory diseases such as asthma and emphysema). Of 4.9 million deaths estimated for older folks 50 to 75 most common causes of death are noncommunicable diseases and unintentional injuries. Of the 1.7 million deaths estimated for children under five, most are due to lower respiratory infections and diarrhoeal diseases.
Environmental risk factors include air, water and soil pollution, chemical exposures, climate change, and ultraviolet radiation.Preventing Disease through Healthy Environments Second Edition 2016