Sources, distribution, and risk assessment of organochlorine pesticides in Nairobi City, Kenya

Copyright © 2020. Published by Elsevier B.V..

The distribution and sources of organochlorine pesticides (OCPs) in air and surface waters were monitored in Nairobi City using triolein-filled semipermeable membrane devices (SPMDs). The SPMDs were extracted by dialysis using n-hexane, followed by cleanup by adsorption chromatography on silica gel cartridges. Sample analysis was done by GC-ECD and confirmed by GC-MS. Separation of means was achieved by analysis of variance, followed by pair-wise comparison using the t-test (p≤ 0.05). The total OCPs ranged between 0.018 - 1.277 ng/m3 in the air and <LOD - 1391.000 ng/m3 in surface waters. Based on the results, the means of Industrial Area, Dandora and Kibera were not significantly different (p≤ 0.05), but were higher (p≤ 0.05) than those of City square and Ngong' Forest. The results revealed non-significant (p≤ 0.05) contribution of long-range transport to OCP pollution in Nairobi City. This indicated possible presence of point sources of environmental OCPs in the city. The water-air fugacity ratios indicated that volatilization and deposition played an important role in the spatial distribution of OCPs in Nairobi City. This indicated that contaminated surface waters could be major sources of human exposure to OCPs, through volatilization. The incremental lifetime cancer risks (ILCR) determined from inhalation of atmospheric OCPs were 2.3745  ×  10-13 - 1.6845  ×  10-11 (adult) and 5.5404  ×  10-13 - 3.9306  ×  10-11 (child) in the order: Dandora > Kibera > Industrial Area > City Square > Ngong' Forest. However, these were lower than the USEPA acceptable risks, 10-6 - 10-4. This study concluded that atmospheric OCPs did not pose significant cancer risks to the residents.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:96

Enthalten in:

Journal of environmental sciences (China) - 96(2020) vom: 01. Okt., Seite 178-185

Sprache:

Englisch

Beteiligte Personen:

Lisouza, Fred Ayodi [VerfasserIn]
Owuor, P Okinda [VerfasserIn]
Lalah, Joseph O [VerfasserIn]

Links:

Volltext

Themen:

Hydrocarbons, Chlorinated
Journal Article
Organochlorine pesticides (OCPs)
Passive sampling
Pesticides
Risk assessment
Sources and distribution
Water-air fugacity ratio

Anmerkungen:

Date Completed 24.08.2020

Date Revised 24.08.2020

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jes.2020.04.046

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM313934398