Environmental health: assesses factors in both the natural and built environments that affect quality of human life: chemical hazards: include spills, exposure to synthetic chemicals that society produces. Anthropogenic human caused factors (ex. smoking, synthetic chemicals) Both synthetic and naturally occurring chemicals can be hazardous (pg. Synthetic: disinfectants, plastics, pharmaceuticals, pesticides: natural: snake venom, poisonous compounds produced by plants as defense mechanisms, toxic metals (arsenic, chromium, mercury) As the human population grows, more people are susceptible to natural, physical hazards (pg. For instance, coastlines are vulnerable to tsunamis and erosion by storms, and mountainous areas are prone to landslides: we engineer landscapes around us in ways that can increase the frequency or severity of natural hazards. Damming and diking rivers to control floods can sometimes lead to catastrophic flooding, and suppressing natural wildfires puts forests at risk of larger, truly damaging fires. Rising sea levels induced by global warming increase susceptibility to coastal erosion.