Contamination of the Water Environment in Malaria Endemic Areas of KwaZulu-Natal, South Africa by DDT and Its Metabolites

Sereda, B; Meinhardt, H. R.

doi:10.1007/s00128-005-0785-x

Cited by 22 publications

(13 citation statements)

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“…Presently, no DDT is used by Illovo Sugar (Malawi) Ltd. either agriculturally or for IRS of dwellings. DDT residues have been detected in soil and water bodies in KwaZulu‐Natal, where DDT has long been used for IRS (Sereda & Meinhardt, 2005). It may be that historic residues exist in the Nchalo plantation from its employment prior to the cessation of usage for agricultural purposes in 1994 and these could continue to exert selective pressure on populations of larval mosquitoes.…”

Section: Discussionmentioning

confidence: 99%

Reduced susceptibility to DDT in field populations of Anopheles quadriannulatus and Anopheles arabiensis in Malawi: evidence for larval selection

Mzilahowa

Ball

Bass

et al. 2008

Medical Vet Entomology

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Bioassays for insecticide resistance in adult mosquitoes were conducted on samples of Anopheles gambiae Giles s.l. (Diptera: Culicidae) species collected as larvae from breeding sites in the lower Shire Valley, Malawi. The results indicate full susceptibility to permethrin, deltamethrin and malathion, but reduced susceptibility to DDT in one sample from Thom (LT(50) of 8.39 min for females and 25.09 min for males). Polymerase chain reaction-based species identification of the mosquitoes assayed revealed a mixture of Anopheles arabiensis Patton and Anopheles quadriannulatus (Theobold). The LT(50) did not differ significantly between species. Genotyping of the L1014F and L1014S kdr alleles showed all mosquito specimens to be homozygous wild type; thus the reduced susceptibility detected is not attributable to target site insensitivity and instead is likely to be metabolic in nature. Anopheles quadriannulatus is characteristically zoophagic and exophilic. Indeed, of 82 Anopheles collected through knockdown collections within dwellings, only one was An. quadriannulatus and the rest were An. arabiensis. They are unlikely, therefore, to have been exposed to selection pressure arising from insecticide-treated net usage or to DDT indoor residual spraying. Therefore, it is suggested that this example of reduced susceptibility to DDT in An. quadriannulatus reflects selection in the larval stages.

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Section: Discussionmentioning

confidence: 99%

Reduced susceptibility to DDT in field populations of Anopheles quadriannulatus and Anopheles arabiensis in Malawi: evidence for larval selection

Mzilahowa

Ball

Bass

et al. 2008

Medical Vet Entomology

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“…The samples were collected during October 2005 at the beginning of the agricultural season. More information on the environment, conditions, and society is available elsewhere (Sharp & le Sueur, 1996;Sereda & Meinhardt, 2005a).…”

Section: Methodsmentioning

confidence: 99%

“…In KwaZulu-Natal (where this study was undertaken), the levels of DDT in freshwater fish (a major protein source at that time) were considered too low (Bouwman et al, 1990a(Bouwman et al, , 2006 to have resulted in the levels detected in human blood and milk (Bouwman et al, 1990b). Insecticide levels in natural water (often a source of drinking water) and sediment were also found to be too low to have been a major contributor toward food uptake of DDT (Sereda & Meinhardt, 2005a). Pollutant residues in bovine milk, even with generally declining levels of DDT in many areas of the world, are still a concern (Heck et al, 2006;Kan & Meijer, 2007).…”

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confidence: 99%

Comparing Water, Bovine Milk, and Indoor Residual Spraying as Possible Sources of DDT and Pyrethroid Residues in Breast Milk

Sereda¹,

Bouwman²,

Kylin³

2009

UTEH

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The presence of pollutants in human breast milk is of major concern, especially in malaria control areas where 1,1,1-trichloro-2, 2-bis(4-chlorophenyl) ethane (DDT) is currently used as indoor residual spray (IRS). The levels of DDT and pyrethroids (PYR) were determined in breast milk, bovine milk, and drinking water from northern KwaZulu-Natal, South Africa. Both reference and exposed mothers used the same market food, but the DDT levels in the exposed mothers (mean SDDT 10 mg/g milk fat) were much higher than for the reference mothers (mean SDDT 1.3 mg/g milk fat). This difference in residue levels indicates uptake from IRSapplied DDT, most likely via air and skin contact, and excludes food as main source of pollutants. DDT levels in bovine milk (mean SDDT 0.15 mg/g milk fat) from the exposed area were less than levels in breast milk from the reference area, and lower than the 20 mg/L maximum residue limit (MRL) set by the FAO. Mean SDDT in water was 0.0065 mg/L, much lower then the World Health Organization (WHO) limit of the sum of all metabolites in drinking water of 1 mg/L, and therefore highly unlikely to have contributed to any extent toward levels in breast milk. Permethrin in breast milk (mean 1.1-1.6 mg/g milk fat) was probably derived from home garden and indoor use, while the other pyrethroids (cypermethrin and cyfluthrin) at lower concentrations were probably derived from food and agricultural exposure. It is postulated that a better understanding of the indoor dynamics of DDT and other insecticides, through a concept of Total Homestead Environment Approach (THEA), is crucial for investigating options of reducing human exposure and uptake under malaria control conditions.

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“…In many rural areas of Africa, subsistence foodstuffs are produced close to homesteads and supplemented with food from markets and shops. We found in previous studies from malariacontrolled areas where DDT is used as IRS, that food (including chicken meat and fat), soil, water, and air are contaminated by DDT (Sereda and Meinhardt, 2005;Sereda et al, 2009;Van Dyk et al, 2010). Cumulative and continuing IRS with DDT since the late 1940s has left a legacy of high concentrations indoors and in soil surrounding homesteads (Van Dyk et al, 2010).…”

Section: Introductionmentioning

confidence: 92%

First report of the concentrations and implications of DDT residues in chicken eggs from a malaria-controlled area

et al. 2015

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Highlights No published studies on DDT in chicken eggs from a malaria controlled area  Median and maximum ΣDDT concentrations were 11 000 and 48 000 ng/g wet mass  The maximum residue limit was exceeded 100 times  Calculated acceptable daily intake was not exceeded (3 eggs/week/60 kg bm)  Reductions of DDT in soil ingested by chickens may reduce human intake via eggs ABSTRACT In malaria endemic areas, where DDT is still used for vector control by indoor residual spraying (IRS), concentrations of DDT in human blood and breast milk are high, and there are indications of human health impact. In order to identify possible avenues of exposure reduction, we created the concept of a Total Homestead Environment Approach (THEA). THEA characterises the interactions between DDT, humans, and biota within and around homesteads. One dietary route of human exposure and uptake of DDT, namely chicken egg consumption, has, to our knowledge, never been published. ΣDDT in eggs from a DDT-sprayed village ranged between 5200-48 000 ng/g wm (wet mass), with a median of 11 000 ng/g wm. On a lipid mass-basis (lm), the mean ΣDDT for eggs from the sprayed village was 100 000 ng/g lm. The maximum egg concentration observed was three orders of magnitude higher than the median. The acceptable daily intake (ADI) was exceeded 2.5 times based 1

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Contamination of the Water Environment in Malaria Endemic Areas of KwaZulu-Natal, South Africa by DDT and Its Metabolites

Cited by 22 publications

References 0 publications

Reduced susceptibility to DDT in field populations of Anopheles quadriannulatus and Anopheles arabiensis in Malawi: evidence for larval selection

Reduced susceptibility to DDT in field populations of Anopheles quadriannulatus and Anopheles arabiensis in Malawi: evidence for larval selection

Comparing Water, Bovine Milk, and Indoor Residual Spraying as Possible Sources of DDT and Pyrethroid Residues in Breast Milk

First report of the concentrations and implications of DDT residues in chicken eggs from a malaria-controlled area

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