Title
Distribution, contents and health risk assessment of metal(loid)s in small-scale farms in the Ecuadorian Amazon: An insight into impacts of oil activities
Date Issued
01 May 2018
Access level
metadata only access
Resource Type
journal article
Author(s)
Maurice L.
Uzu G.
Becerra S.
López F.
Ochoa-Herrera V.
Ruales J.
Schreck E.
Université de Toulouse
Publisher(s)
Elsevier B.V.
Abstract
In the last 50 years, oil extraction activities in the Northeast Amazonian Region (NAR) of Ecuador impacted ecosystems and may still affect the local population health. To our knowledge, no previous studies have determined the concentrations of metal(loid)s in the oil Ecuadorian Amazon environment. A total of 15 small farms, located in the Orellana and Sucumbíos provinces, were sampled in order to determine the concentrations of As, Ba, Co, Cu, Cd, Cr, Mn, Mo, Ni, Pb, V and Zn in soils, crops, drinking water and air (PM10). Among non-essential metal(loid)s, Ba concentrations in soils exceeded the Ecuadorian limits of 200 mg kg− 1 in 53% of the sampling sites. In crops, Cd concentrations in cacao and Pb in manioc exceeded the FAO/WHO recommendations. In drinking water and PM10, regulated metal(loid)s did not exceed the international thresholds. Nevertheless metals such as Ba and Mo showed the highest annual mean concentrations in PM10 in both sampling sites. Natural (bedrock, volcanic ashes) and anthropogenic (oil activities, agrochemical products) sources could explain the high content of some meta(loid)s in the environment. According to the hazard quotient and cancer risk indexes, crops and water ingestion represent 71% and 88% of the exposure pathways for non-carcinogenic elements in adults and children respectively while inhalation is the main exposure pathways for carcinogenic elements for the whole population. Both indexes were 2 to 13 times higher than the US EPA recommended values. However, estimates of exposure pathways should be considered taking into account the risk perception of residents: they may be overestimated for people who are able to change their dietary and/or agricultural practices to limit their exposure, or underestimated in the case of persons who are socio-economically vulnerable and who cannot leave the impacted areas.
Start page
106
End page
120
Volume
622-623
Language
English
OCDE Knowledge area
Agronomía Ingeniería del Petróleo, (combustibles, aceites), Energía, Combustibles
Scopus EID
2-s2.0-85036463441
PubMed ID
Source
Science of the Total Environment
ISSN of the container
00489697
Sponsor(s)
The authors would like to thank the French National Agency of Research for the financial aid in the frame of the ANR-MONOIL Project N°ANR-13-SENV-0003-01 . We want to also express our gratitude to local small farmers for providing us crops and soil samples, especially to the Ramirez, Martinez, Aveiga and Garcia families. We would like to thank Hélène Guyard from IGE for settling active air samplers, Mathieu Boidot for statistical advises and R graphical representations, and the 4 reviewers for their careful reading that help us to largely improve our manuscript with their relevant comments. V.O.H. would like to acknowledge Universidad San Francisco de Quito (USFQ) and the Institute of Geography for financial support. Finally we want to thank the National Program of Innovation for the Competitiveness and Productivity of Peru, Innovate Peru, for the PhD study grant N°139-Innóvate Perú-BDE-2014 of the first author.
Sources of information: Directorio de Producción Científica Scopus