Fate of Pesticides in the Arid Subtropics, Botswana, Southern Africa

Chubashini Shunthirasingham, Baagi T. Mmereki, Wellington Masamba, Catherine E. Oyiliagu, Ying D. Lei, Frank Wania

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Despite a history of pesticide usage, few data exist on their concentrations in air and soil of Southern Africa. To add to the understanding of the processes controlling the fate of organic contaminants in arid regions, the levels, spatial trends, and seasonal variability of pesticides were studied in air and soil from Botswana. XAD resin-based passive air samplers (PAS) were deployed at 15 sites across the country from May 2006 to May 2007. Soil samples were collected from the vicinity of nine of the PAS sampling sites. In addition, 27 24-h high-volume air samples were collected in Maun, at the southeastern edge of the Okavango Deka, every two weeks for one year. Levels of pesticides in PAS were low, with alpha-endosulfan and lindane being most abundant Concentrations in soils were extremely low and only soils with high organic carbon contained notable amounts of dieldrin and traces of other pesticides. In particular, air and soil from the Okavango Delta had very low levels even though the area had repeatedly been sprayed with DDT and endosulfan in the past Air samples from Eastern Botswana, where the majority of the population lives, contained higher levels. Higher air concentrations of a-endosulfan occurred during summer and higher HCB levels occurred in winter. This seasonality was related with neither minor seasonal changes in temperature nor hydrological seasonal events such as the rainy season or the flooding of the Okavango Delta. Thus, the observed spatial and seasonal patterns are more likely related to pesticide usage pattern than to environmental factors or historical use. High temperature and low organic matter content limit the uptake capacity of most subtropical soils for pesticides. No evidence was found that sorption to dry mineral matter plays a major role. Arid soils in subtropical regions are therefore neither a major reservoir of organic contaminants nor do they constitute a significant long-term source of pesticides to the atmosphere.
Original languageEnglish
Pages (from-to)8082-8088
Number of pages7
JournalEnvironmental Science & Technology
Volume44
Issue number21
DOIs
Publication statusPublished - 2010

Fingerprint

Pesticides
pesticide
Soils
air
Air
Endosulfan
endosulfan
soil
sampler
Impurities
Hexachlorobenzene
Dieldrin
Southern Africa
Arid regions
Lindane
DDT
pollutant
subtropical region
dieldrin
hexachlorobenzene

Cite this

Shunthirasingham, C., Mmereki, B. T., Masamba, W., Oyiliagu, C. E., Lei, Y. D., & Wania, F. (2010). Fate of Pesticides in the Arid Subtropics, Botswana, Southern Africa. Environmental Science & Technology, 44(21), 8082-8088. https://doi.org/10.1021/es1024788
Shunthirasingham, Chubashini ; Mmereki, Baagi T. ; Masamba, Wellington ; Oyiliagu, Catherine E. ; Lei, Ying D. ; Wania, Frank. / Fate of Pesticides in the Arid Subtropics, Botswana, Southern Africa. In: Environmental Science & Technology. 2010 ; Vol. 44, No. 21. pp. 8082-8088.
@article{96e27e6421ea40c7945acdede1d9e15d,
title = "Fate of Pesticides in the Arid Subtropics, Botswana, Southern Africa",
abstract = "Despite a history of pesticide usage, few data exist on their concentrations in air and soil of Southern Africa. To add to the understanding of the processes controlling the fate of organic contaminants in arid regions, the levels, spatial trends, and seasonal variability of pesticides were studied in air and soil from Botswana. XAD resin-based passive air samplers (PAS) were deployed at 15 sites across the country from May 2006 to May 2007. Soil samples were collected from the vicinity of nine of the PAS sampling sites. In addition, 27 24-h high-volume air samples were collected in Maun, at the southeastern edge of the Okavango Deka, every two weeks for one year. Levels of pesticides in PAS were low, with alpha-endosulfan and lindane being most abundant Concentrations in soils were extremely low and only soils with high organic carbon contained notable amounts of dieldrin and traces of other pesticides. In particular, air and soil from the Okavango Delta had very low levels even though the area had repeatedly been sprayed with DDT and endosulfan in the past Air samples from Eastern Botswana, where the majority of the population lives, contained higher levels. Higher air concentrations of a-endosulfan occurred during summer and higher HCB levels occurred in winter. This seasonality was related with neither minor seasonal changes in temperature nor hydrological seasonal events such as the rainy season or the flooding of the Okavango Delta. Thus, the observed spatial and seasonal patterns are more likely related to pesticide usage pattern than to environmental factors or historical use. High temperature and low organic matter content limit the uptake capacity of most subtropical soils for pesticides. No evidence was found that sorption to dry mineral matter plays a major role. Arid soils in subtropical regions are therefore neither a major reservoir of organic contaminants nor do they constitute a significant long-term source of pesticides to the atmosphere.",
author = "Chubashini Shunthirasingham and Mmereki, {Baagi T.} and Wellington Masamba and Oyiliagu, {Catherine E.} and Lei, {Ying D.} and Frank Wania",
year = "2010",
doi = "10.1021/es1024788",
language = "English",
volume = "44",
pages = "8082--8088",
journal = "Environmental Science & Technology",
issn = "0013-936X",
publisher = "American Chemical Society",
number = "21",

}

Shunthirasingham, C, Mmereki, BT, Masamba, W, Oyiliagu, CE, Lei, YD & Wania, F 2010, 'Fate of Pesticides in the Arid Subtropics, Botswana, Southern Africa', Environmental Science & Technology, vol. 44, no. 21, pp. 8082-8088. https://doi.org/10.1021/es1024788

Fate of Pesticides in the Arid Subtropics, Botswana, Southern Africa. / Shunthirasingham, Chubashini; Mmereki, Baagi T.; Masamba, Wellington; Oyiliagu, Catherine E.; Lei, Ying D.; Wania, Frank.

In: Environmental Science & Technology, Vol. 44, No. 21, 2010, p. 8082-8088.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Fate of Pesticides in the Arid Subtropics, Botswana, Southern Africa

AU - Shunthirasingham, Chubashini

AU - Mmereki, Baagi T.

AU - Masamba, Wellington

AU - Oyiliagu, Catherine E.

AU - Lei, Ying D.

AU - Wania, Frank

PY - 2010

Y1 - 2010

N2 - Despite a history of pesticide usage, few data exist on their concentrations in air and soil of Southern Africa. To add to the understanding of the processes controlling the fate of organic contaminants in arid regions, the levels, spatial trends, and seasonal variability of pesticides were studied in air and soil from Botswana. XAD resin-based passive air samplers (PAS) were deployed at 15 sites across the country from May 2006 to May 2007. Soil samples were collected from the vicinity of nine of the PAS sampling sites. In addition, 27 24-h high-volume air samples were collected in Maun, at the southeastern edge of the Okavango Deka, every two weeks for one year. Levels of pesticides in PAS were low, with alpha-endosulfan and lindane being most abundant Concentrations in soils were extremely low and only soils with high organic carbon contained notable amounts of dieldrin and traces of other pesticides. In particular, air and soil from the Okavango Delta had very low levels even though the area had repeatedly been sprayed with DDT and endosulfan in the past Air samples from Eastern Botswana, where the majority of the population lives, contained higher levels. Higher air concentrations of a-endosulfan occurred during summer and higher HCB levels occurred in winter. This seasonality was related with neither minor seasonal changes in temperature nor hydrological seasonal events such as the rainy season or the flooding of the Okavango Delta. Thus, the observed spatial and seasonal patterns are more likely related to pesticide usage pattern than to environmental factors or historical use. High temperature and low organic matter content limit the uptake capacity of most subtropical soils for pesticides. No evidence was found that sorption to dry mineral matter plays a major role. Arid soils in subtropical regions are therefore neither a major reservoir of organic contaminants nor do they constitute a significant long-term source of pesticides to the atmosphere.

AB - Despite a history of pesticide usage, few data exist on their concentrations in air and soil of Southern Africa. To add to the understanding of the processes controlling the fate of organic contaminants in arid regions, the levels, spatial trends, and seasonal variability of pesticides were studied in air and soil from Botswana. XAD resin-based passive air samplers (PAS) were deployed at 15 sites across the country from May 2006 to May 2007. Soil samples were collected from the vicinity of nine of the PAS sampling sites. In addition, 27 24-h high-volume air samples were collected in Maun, at the southeastern edge of the Okavango Deka, every two weeks for one year. Levels of pesticides in PAS were low, with alpha-endosulfan and lindane being most abundant Concentrations in soils were extremely low and only soils with high organic carbon contained notable amounts of dieldrin and traces of other pesticides. In particular, air and soil from the Okavango Delta had very low levels even though the area had repeatedly been sprayed with DDT and endosulfan in the past Air samples from Eastern Botswana, where the majority of the population lives, contained higher levels. Higher air concentrations of a-endosulfan occurred during summer and higher HCB levels occurred in winter. This seasonality was related with neither minor seasonal changes in temperature nor hydrological seasonal events such as the rainy season or the flooding of the Okavango Delta. Thus, the observed spatial and seasonal patterns are more likely related to pesticide usage pattern than to environmental factors or historical use. High temperature and low organic matter content limit the uptake capacity of most subtropical soils for pesticides. No evidence was found that sorption to dry mineral matter plays a major role. Arid soils in subtropical regions are therefore neither a major reservoir of organic contaminants nor do they constitute a significant long-term source of pesticides to the atmosphere.

U2 - 10.1021/es1024788

DO - 10.1021/es1024788

M3 - Article

VL - 44

SP - 8082

EP - 8088

JO - Environmental Science & Technology

JF - Environmental Science & Technology

SN - 0013-936X

IS - 21

ER -