Pumping in a dusty environment

Would like to ask how should I ensure that my milk is not "contaminated" if I occasionally have to go onsite to dusty environments. I am worried that my clothes might contain some fine dust from the site. Anyone in a similar situation? Any advice? The nursing room is clean. Should I prepare a separate set of clothes to change into to pump? But sometimes I get sweaty and sticky from going onsite #Needadvice .