▁to ▁the ▁effects ▁of ▁gas / part icle ▁partition ing , ▁season al ▁sources , ▁and ▁clim atic ▁conditions . ▁ ▁S ources ▁▁ ▁Ch lor in ated ▁poly cyc lic ▁a rom atic ▁hydro car b ons ▁are ▁generated ▁by ▁comb ust ion ▁of ▁organ ic ▁comp ounds . ▁Cl - PA H s ▁enter ▁the ▁environment ▁from ▁a ▁multip licity ▁of ▁sources ▁and ▁tend ▁to ▁persist ▁in ▁soil ▁and ▁in ▁partic ulate ▁matter ▁in ▁air . ▁Environment al ▁data ▁and ▁emission ▁sources ▁analysis ▁for ▁Cl - PA H s ▁reve al ▁that ▁the ▁dominant ▁process ▁of ▁generation ▁is ▁by ▁reaction ▁of ▁PA H s ▁with ▁ch lor ine ▁in ▁py ros yn thesis . ▁Cl - PA H s ▁have ▁commonly ▁been ▁detected ▁in ▁tap ▁water , ▁fly ▁ash ▁from ▁an ▁inc iner ation ▁plant ▁for ▁radio active ▁waste , ▁em issions ▁from ▁coal ▁comb ust ion ▁and ▁municipal ▁waste ▁inc iner ation , ▁autom obile ▁exhaust , ▁snow , ▁and ▁urban ▁air . ▁They ▁have ▁also ▁been ▁detected ▁in ▁electronic ▁was tes , ▁work shop - floor ▁dust , ▁veget ation , ▁and ▁surface ▁soil ▁collected ▁from ▁the ▁vic inity ▁of ▁an ▁electronic ▁waste ▁( e - w aste ) ▁rec y cling ▁facility ▁and ▁in ▁surface ▁soil ▁from ▁a ▁chemical ▁industrial ▁complex ▁( com pr ising ▁a ▁co ke - oven ▁plant , ▁a ▁coal - f ired ▁power ▁plant , ▁and ▁a ▁ch lor - alk ali ▁plant ), ▁and ▁agricult ural ▁areas ▁in ▁central ▁and ▁eastern ▁China