In homes, what common material used in construction before 1973 is recognized as a potential health hazard?

The correct answer is asbestos, which is a material that was commonly used in construction prior to 1973 and is recognized as a significant health hazard. Asbestos has been used for its fire-resistant properties and insulation capabilities in buildings, particularly in insulation, roofing, and flooring materials. The health risks associated with asbestos exposure are well-documented, including serious conditions such as asbestosis, lung cancer, and mesothelioma. Due to these health concerns, the use of asbestos in construction has been heavily regulated and largely phased out.

While lead paint is also a health hazard, it was not solely unique to homes built before 1973; it was used until 1978. Vermiculite insulation may contain asbestos, but it is not recognized solely for its health hazards independently of the context in which it was used. Straw bale construction is a modern alternative method and not a common material used in conventional construction prior to 1973. Therefore, asbestos is the most fitting answer in the context of the question regarding health hazards in homes built before that year.