Often, lofts are sprayed with lindane as a condition of mortgages. We go into pubs, schools, homes or any other variety of buildings which might have been sprayed recently with lindane or comparable chemicals. We would not know that we were so exposed. We absorb lindane by breathing the gas and vapours. It goes straight into the lungs and into the bloodstream.
Fine dust can follow the same route.
Larger particles are trapped in the nasal passages or the mucus escalator of the bronchial tubes. It is not necessary to have direct contact with the chemical. It can be swallowed because food and water can be contaminated directly by exposure to lindane. Lindane can be absorbed into the air. It mixes with food and water.