International Journal of Earth Sciences Knowledge and Applications
Yazarlar: Lloyd Shorai PİSA, Henk BOUWMAN
Konular:Yerbilimleri, Ortak Disiplinler
Anahtar Kelimeler:Indoor residual spraying,DDT,Exposure,Tukey method,Outside dust
Özet: An assessment of indoor air, indoor dust, and outdoor dust DDT concentration was conducted to assess the lefts of DDT residents in Indoor Residual Sprayed (IRS) areas were potentially exposed to. The study was carried out in Thohoyandou, Vhembe Limpopo at three villages, with one used as a control site. The results for DDT metabolites show that DDT concentrations increased during the spraying period and o,p’-DDE concentrations were highest compared to all other metabolites throughout the sampling period. There is a statistical difference in the mean concentrations of DDT isomers sampled at T0T and the other sampling intervals. o,p’-DDE concentrations also significantly dropped an hour after spraying. The concentrations remained also constant throughout the 84-day sampling period for all other metabolites. Dust concentration indoor were generally low at the two sampled sites, mainly because of the frequent sweeping of huts. Results show that the mean concentrations recorded an hour before sampling are significantly different from mean concentrations from sampling collected and hour and 24 hours after IRS. However outdoor dust recorded similar concentrations and both the sprayed and control site. Soil samples collected at TV and DV outside huts indicate the presence of DDT at both sites. p,p’-DDE concentrations were highest at both sites with concentrations of 16 µg/kg and 14 µg/kg respectively. o,p’-DDT concentrations were lowest at both sites. Samples from both sites displayed very similar results with very little difference in metabolite concentrations. A comparison of air and dust samples showed that air samples had higher levels of DDT and its metabolites with the most significant difference noted in o,p’-DDT and p,p’-DDT concentration. Indoor air recorded a concentration of 1.4 µg/m3 with a concentration of 0.1 µg/m2 being recorded for o,p’-DDT on the dust floor. p,p’-DDT concentration was 2.2 µg/m3 in air and 1.1 µg/m2 on floor dust.