OSHA (Occupational Safety and Health Administration) identifies several health hazards that construction workers may be exposed to, including:

Respirable crystalline silica dust, which can cause lung cancer and other respiratory diseases
Noise, which can lead to hearing loss
Lead, which can cause neurological damage
Asbestos, which can cause lung cancer and mesothelioma
Ergonomic hazards, such as repetitive motions and awkward postures, which can cause musculoskeletal disorders
Hazardous chemicals and materials, such as solvents and pesticides, which can cause a variety of health problems
OSHA provides guidelines and regulations to help employers protect workers from these and other hazards.