If a child is found poisoned in a rental, Maine law requires testing of the unit and expensive abatement if the unit is determined to have:

In Maine, the law specifically addresses the health risks associated with lead paint and lead paint hazards, particularly in residential properties built before 1978 when the use of lead-based paint was banned for residential purposes. If a child is found to have been poisoned, typically from lead exposure, it triggers a legal obligation for landlords to ensure their properties are safe. This includes testing for lead paint and any associated hazards, as well as undertaking necessary abatement measures to remove or mitigate the risks of lead exposure.

The focus on lead is due to its severe health implications for children, including developmental delays and various other health complications. The law recognizes that these hazards can persist in older buildings and needs to be addressed promptly to ensure tenant safety, especially for vulnerable populations like children.

In contrast, while concerns about asbestos, arsenic, and mold are valid and important in a rental context, they do not carry the same specific legal mandate regarding testing and abatement triggered directly by a poisoning incident involving children as lead hazards do. Therefore, the requirement for testing and abatement in cases of lead paint or lead paint hazards is what makes this option the correct answer.