Exposure assessment of polybrominated diphenyl ethers (PBDEs) in Mexican children.

Flame retardants (FRs) constitute a group of compounds that are added to materials in order to suppress, reduce, or delay fire. At present the most used FRs are the polybrominated diphenyl ethers (PBDEs), and diverse studies have found individuals exposed to them. However, few studies have reported data in children. The objective of this report was to assess PBDEs levels in children of six communities in México. During the year 2006 we analyzed a total of 173 healthy children (aged 6-13 years old). Plasma samples were taken and quantified (gas chromatography/mass spectrometer) for PBDEs. Six PBDEs congeners (BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, and BDE-209) were quantified in blood serum. We detected exposure to PBDEs in all the communities. The total PBDEs levels ranged from no detectable (nd) to 43.4 ng g(-1) lipid, the dominant PBDE congener was BDE-47, followed by BDE-100, BDE-99 and BDE-153, whereas the levels of BDE-209 were below LOD. Children living in an industrial and urban area (Cd. Juarez, Chih) had the highest levels of PBDEs, approximately two times that of children living in El Refugio, S.L.P. (a rural area) or in Milpillas, S.L.P. (municipal landfill) and 4-5 times higher than levels found in children living in San Luis Potosi, S.L.P. (urban area), in Chihuahua, Chih. (urban area), and San Juan Tilapa, Edo. Mex. (municipal landfills). Results cannot be generalized since the communities selected are not representative of the Mexican population. However, they do indicate that Mexican children are exposed to PBDEs.

Exposure assessment of persistent organic pollutants and metals in Mexican children.

Environmental policies in Mexico have contributed to the reduction in the production or use of some persistent organic pollutants (POPs) and metals. However, monitoring of POPs concentrations in humans living in hot spots is lacking. Therefore, the objective of this study was to conduct a screening for POPs and metals first in Mexican children living in high-risk areas. During the year 2004, we analyzed a total of 229 healthy children (aged 6-12 years old) who resided in communities located in nine Mexican states. Organochlorine insecticides, PCBs and metals were quantified in plasma and urine samples. We detected p'p-DDE in all the children; moreover, p'p-DDT, lindane and hexachlorobenzene were detected respectively in 14%, 85% and 10% of the children studied. Measurable levels of PCBs were recorded in only one community, where six of 14 PCB congeners assayed were detected (numbers 52, 118, 138, 153, 170 and 180). All the children had detectable levels of lead in their blood (mean level, 4.6 microg dL(-1)); furthermore, 57% of the children studied had levels higher than 5.0 microg/dL. The mean level of urinary arsenic (UAs) for all the children was 22.35 microg g(-1) creatinine and 15% of those children had concentrations of UAs above 50 microg g(-1) creatinine. For cadmium, the mean urinary level was 0.78 microg g(-1) creatinine, and only one percent of the children had values above 2.0 microg g(-1) creatinine. The results cannot be generalized since the communities selected are not representative of the Mexican population; however, they indicate that Mexican children are exposed to chemicals and some at risk levels.