Which of the following is an advantage of using ultraviolet (UV) light for water disinfection?

The use of ultraviolet (UV) light for water disinfection offers the significant advantage of not producing harmful byproducts. When water is treated with UV light, microorganisms such as bacteria, viruses, and protozoa are effectively inactivated, preventing the spread of waterborne diseases without the introduction of additional chemicals into the water supply. This is particularly important in public health, as it eliminates the risk associated with chemical disinfection methods, which can sometimes lead to the formation of hazardous byproducts like trihalomethanes or haloacetic acids.

The other options do not accurately represent the benefits of UV disinfection. While UV light is effective for disinfection, it does not remove heavy metals from water, nor is it necessarily the cheapest method available compared to other techniques like chlorination. Additionally, UV disinfection does not improve the taste of water, as this process focuses solely on microbial inactivation rather than altering physical or chemical properties that could influence taste. Thus, the lack of harmful byproducts is a distinct and important advantage of using UV light for disinfecting water.