Feasibility of using low density polyethylene sheets to detect atmospheric organochlorine pesticides in Alexandria, Egypt

Egypt is a major agricultural country in Africa with a known past of organochlorine pesticides (OCPs) application, yet data on atmospheric levels of OCPs in Egypt is sparse. Low density polyethylene (LDPE) passive samplers were therefore deployed for 3 weeks each at 11 locations in July, 2010 and January, 2011 in Alexandria to screen for gas-phase OCPs. Performance reference compounds were used to investigate the uptake kinetics. Field-derived sampler-air partitioning coefficients (KPE-As) for OCPs were significantly correlated against the compounds' subcooled liquid vapor pressure (log PL): [log KPE-A = −0.77 ± 0.07*log PL + 6.35 ± 0.13 (R2 = 0.90; n = 17; SE = 0.19; p < 0.001)]. Estimated and measured OCP concentrations in Alexandria agreed well (factor difference ≤ 2) indicating the feasibility of monitoring OCPs using LDPEs. OCP concentrations ranged from <LOD to 168 pg/m3. Calculated isomeric ratios indicated recent usage of chlordanes and endosulfans. -- Highlights: •The feasibility of using LDPE as passive air samplers for OCPs was investigated. •PRCs were used to investigate the exchange kinetics and equilibration stages. •KPE-As for OCPs were predicted from a regression relation with PL. •Estimated (from LDPE) and measured (active sampler) OCP concentrations agreed well. •OCP levels, sources and temporal variations were studied in Alexandria using LDPE. -- LDPE passive air samplers spiked with PRCs can be used as a practical low cost technique for monitoring gas phase OCPs in Egypt