A chemical, triclosan, an antibacterial additive in some cleaning compounds can affect calcium channels that regulate cell activity. Researchers have identified levels of triclosan that can be lethal to mice in humans. It is believed that this chemical can cause a reduction in muscle mass in humans.
Some individuals who are adversely affect by chemicals, molds, bacteria and other contaminants in water damaged buildings use antibacterial products to prevent exposures to biological agents. If products contain triclosan are used, these individuals might experience muscle loss they attribute to re-exposure to mold, when the culprit is actually the cleaners or personal care products that they use.
For more information on triclosan go to http://www.sciencenews.org/view/generic/id/343045/title/Antibacterial_agent_can_weaken_musc