Passive Air Sampling of Organochlorine Pesticides in Mexico

Abstract

The spatial and temporal variation of organochlorine pesticides (OCs) in air across Mexico was investigated by deploying passive samplers at eleven stations across the country during 2005-2006. Integrated samples were taken over three-month periods and quantified for DDT compounds, endosulfans, toxaphenes, components of technical chlordane, hexachlorocyclohexanes (HCHs), and dieldrin. Enantiomers of chiral chlordanes and o,p'-DDT were determined on chiral stationary phase columns as an indicator of source and age. Results are discussed in combination with pumped air samples taken at four other stations in southern Mexico during 2002-2004. DDT and its metabolites, endosulfan and toxaphene were the most abundant OCs detected in all sampling sites. Atmospheric concentrations of SigmaDDT (p,p'-DDT + o,p'-DDT + p,p'-DDE + o,p'-DDE + p,p'-DDD + o,p'-DDD) ranged from 15 to 2360 pg m(-3) with the highest concentrations found in southern Mexico and the lowest found in northern and central Mexico. A fresher DDT residue was observed at sites with greater DDT use and in the southern part of the country, as shown from the higher FDDTe = p,p'-DDT/(p,p'-DDT + p,p'-DDE) and nearly racemic o,p'-DDT. This agrees with the former heavy use of DDT in the endemic malarious area of the country. A local hotspot of endosulfan was identified at an agricultural area in Mazatlan, Sinaloa, with a annual mean concentration of SigmaENDO (endosulfans I + II + endosulfan sulfate) = 26,800 pg m(-3). At this site, higher concentrations of SigmaENDO were recorded during the winter (November to February) and spring (February to May) periods. From back trajectory analysis, this coincides with a shift in the air mass coming from the Pacific Ocean (May to November) to the inland agricultural area (November to May). The elevated SigmaENDO observed is likely due to the local agricultural usage. HCHs, chlordanes, transnonachlors, and dieldrin were more evenly distributed across the country likely due to them being aged residues and more diffuse in the environment. In contrast, hotspots of endosulfans, DDTs, and toxaphenes were observed as they were heavily used in localized agricultural or malarious regions of Mexico.

Human health risk of dietary intake of organochlorine pesticide residues in bovine meat and tissues from Veracruz, México

“…These concentrations detected in lung tissues represent possible current regional and seasonal background values of DDTs levels monitored in air within the central agrarian region of Veracruz by Wong et al (2009) who observed fresher DDT residues at Veracruz, México and also o,p 0 -DDT. This agrees with the former heavy use of DDT in this endemic malarious area of the country.…”

“…This distribution pattern is different to the distribution in female pork tissues reported by Covaci et al (2004): fat > muscle > liver > lung > kidney > heart > brain. These high levels of p,p'-DDE detected in lung tissues could be related to the elevated atmospheric concentrations of RDDT that have been reported in air (p,p 0 -DDT + o,p 0 -DDT + p,p 0 -DDE + o,p 0 -DDE + p,p 0 -DDD + o,p 0 -DDD) of 1166.7 pg m À3 in Veracruz, Mexico (Wong et al, 2009).…”

Improved correction method for using passive air samplers to assess the distribution of PCNs in the Dongjiang River basin of the Pearl River Delta, South China

“…For the same PUF sampler using for the same targets, the sampling rate mostly depends on the environment factors, which can be corrected by the DC recoveries. The sampling rates calculated using the improved method are comparable to the rates of Moeckel et al (2009), Wong et al (2009), and Pozo et al (2004. Fig.…”

Semivolatile Organic Compounds in Residential Air along the Arizona−Mexico Border

“…The chemicals identified by the GC-MS screening approach demonstrated here may be quantified by much more selective analytical methods specifically developed for the analytes of interest. Passive sampling approaches such as SPMDs or PUF samplers, used in a recent air sampling campaign for pesticides in Mexico (40), would be amenable to the numbers of samples required for large-scale human health and exposure assessments. …”