Provide two examples of chemical hazards and summarize their primary health endpoints.

• A. Benzene — hematotoxicity and leukemia risk; Formaldehyde — nasopharyngeal cancer risk and irritant effects.
• B. Benzene — liver toxicity; Formaldehyde — neurotoxicity.
• C. Benzene — kidney toxicity; Formaldehyde — cardiovascular risk.
• D. Benzene — only acute irritation; Formaldehyde — only skin sensitization.

Answer: (A)

Two chemical hazards illustrate how different toxic actions translate into key health outcomes. Benzene is known for hematotoxicity—it damages bone marrow and disrupts blood cell formation—which underlies an increased risk of leukemia. Formaldehyde chiefly irritates the mucous membranes of the eyes, nose, and throat, and has a well-established link to nasopharyngeal cancer with long-term exposure; irritation is a common acute effect, and cancer risk is the major long-term endpoint. These endpoints help guide monitoring and prevention: blood studies and leukemia risk vigilance for benzene, and monitoring for respiratory irritation with attention to cancer risk for formaldehyde. The other descriptions don’t align with benzene’s hematologic/carcinogenic profile or with formaldehyde’s combination of irritation and nasopharyngeal cancer risk.