Question

what influences environmental health?

increasing the number of voters
decreasing homicides
improving access to quality housing
decreasing eating disorders

Explanation:

Environmental health is influenced by factors related to the environment and living conditions. Improving access to quality housing directly impacts environmental health as it relates to living spaces, which are part of the environment. Increasing the number of voters is a political aspect, decreasing homicides is a crime - related aspect, and decreasing eating disorders is a health - behavior aspect not directly tied to environmental health.

Answer:

improving access to quality housing