Natalia Bravo

Background/aim Organophosphate (OP) and pyrethroid (PYR) pesticides have a strong potential to disrupt the brain and nervous system of insects. This neurotoxic effect is not highly selective and therefore the compounds are also toxic to other non-target species, including humans. Once in the human body, OP and PYR pesticides are typically metabolised and excreted in urine within 4–48 hours after exposure. Methods A new analytical methodology for the quantification of OP and PYR urinary metabolites has been developed taking into account the wide range of concentrations of these compounds in humans from general and highly exposed populations (e.g. rural or agricultural areas). Six biomarkers of OP pesticides and two biomarkers of PYR compounds have been quantified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). This methodology has been externally checked-out by participation in rounds of the G-Equas programme. A total of 125 urine samples from two adult Spanish populations have been analysed: farmworkers (n=45) and individuals living in urban and rural areas (n=80) from Catalonia and Galicia. Results The most abundant OP metabolites were PNP (metabolite of parathion and methyl paration, found in all samples analysed), followed by TCPY (metabolite of chlorpyrifos, found in 95% of the samples) and DEAMPY (metabolite of pirimiphos, 77% of detection), with median concentrations of 1.8 ng/ml, 1.1 ng/ml and 3.2 ng/ml, respectively. None of the samples had MDA (metabolite of malathion), and a few of them (<5%) had detectable concentrations of IMPY and CMHC (metabolites of diazinon and coumaphos, respectively). Concerning PYR metabolites, 3-PBA (metabolite of several commercial pyrethroids) was found in 81% of the samples (median concentration of 1.5 ng/ml) and 4-F-3-PBA (metabolite of cyfluthrin) was found in half of the cohort, with a median concentration of 0.076 ng/ml. Conclusion Metabolites of OP and PYR pesticides were observed in both farmworkers and general populations living in rural and urban areas, the former showing twofold average concentrations of OP metabolites than the second. These differences are consistent with occupational activity. The results show that both populations are generally exposed to pesticides such as chlorpyriphos, pirimiphos and parathion.

The EMASAR study is the first study to describe the body burden of OCs in Argentinian women after delivery. In total, 698 maternal serum samples from Salta (n = 498) and Ushuaia (n = 200) were collected in 2011-2012 and analyzed for a total of 7 polychlorinated biphenyls (PCBs) and 12 pesticide-related compounds. Only 11 of the compounds had detection rates above 60% in one or both places. Compared with Ushuaian women, those from Salta exhibited higher lipid-adjusted concentrations of p,p'-DDE, p,p'-DDT, β-HCH, and PCB 118 (p ≤ 0.003), with no differences in concentrations of PCB 153 and 138. After controlling for age, parity and heritage (born in the province or migrated there from other regions of Argentina), concentrations of p,p'-DDE, p,p'-DDT, β-HCH and all PCBs were significantly higher in Salta natives compared with Ushuaia natives or migrants (p ≤ 0.010). No variations between native and migrated Ushuaian women were observed other than for PCB 153 (6.1 versus...

Isotope dilution solid phase extraction UPLC-MS/MS has been used to develop a robust and rapid methodology for the determination of eight specific metabolites of organophosphate and pyrethroid pesticides in human urine. The use of methanol:acetone (25:75v/v) affords an improvement in extraction efficiency in comparison to these individual solvents. The use of synthetic urine improves selectivity and limits of detection for the calibration straight lines. The method provides detection limits of 14-69pg/ml and 18-19pg/ml for the organophosphate and pyrethroid metabolites, respectively. Urine analyses of these metabolites in urban non-occupationally exposed individuals and farm workers shows that ingestion of these pesticides occurred in both populations. The concentrations of organophosphate pesticide metabolites in the latter were twofold than those from non-exposed populations.

The occurrence of organohalogen compounds in venous serum from post-partum mothers from two Argentinian cities, Salta and Ushuaia, has been investigated (n = 698). 4,4'-DDE was the most abundant compound in these cities, with geometric means of 33 and 67ng/g lipid weight, respectively. City of residence, age and parity were the main determinants of the accumulation of these compounds. Hexachlorobenzene (HCB) was the second most abundant pollutant in Ushuaia, 8.7ng/g lipid, and β-hexachlorocyclohexane (β-HCH) in Salta, 7.8ng/g lipid. Decabromodiphenyl ether was higher in Ushuaia than Salta, 8.2 and 4.1ng/g lipid, respectively. The predominance of β-HCH, 4,4'-DDE and 4,4'-DDT in Salta was related with higher use of pesticides for agricultural applications. The observed higher concentrations of 4,4'-DDE and 4,4'-DDT in the mothers from rural+semi-urban sites than in urban areas were consistent with this agricultural origin. In addition, the most volatile organochlor...

The first examples of enantioselective addition of anthrones to α,β-unsaturated aldehydes are disclosed. The reaction was performed at −40 °C achieving high yields and enantioselectivities. ... The first examples of enantioselective addition of anthrones to α,β- ...