Muscle pain can result from exposure to a variety of toxic substances. These include heavy metals such as lead and mercury, which can accumulate in the body and affect muscle function. Certain drugs, notably statins used for lowering cholesterol, are also known to cause muscle pain as a side effect. Additionally, exposure to organophosphates, commonly found in pesticides, can lead to muscle cramps and pain due to their inhibitory effect on acetylcholinesterase.