Simplify the following text for a Grade 17 native English-speaking person.
Original: Epidemiological studies are aimed , where possible , at revealing unbiased relationships between ( ( Exposure Assessment Exposure exposures ) ) such as alcohol or smoking , biological agents , stress , or chemicals to mortality or morbidity .
Simplified: Epidemiological studies are aimed , where possible , at revealing unbiased relationships between exposures such as alcohol or smoking , biological agents , stress , or chemicals to mortality or morbidity .