Geologic and anthropogenic sources of contamination in settled dust of a historic mining port city in northern Chile: health risk implications

Abstract

Chile is the leading producer of copper worldwide and its richest mineral deposits are found in the Antofagasta Region of northern Chile. Mining activities have significantly increased income and employment in the region; however, there has been little assessment of the resulting environmental impacts to residents. The port of Antofagasta, located 1,430 km north of Santiago, the capital of Chile, functioned as mineral stockpile until 1998 and has served as a copper concentrate stockpile since 2014. Samples were collected in 2014 and 2016 that show elevated concentrations of As, Cu, Pb, and Zn in street dust and in residents’ blood (Pb) and urine (As) samples. To interpret and analyze the spatial variability and likely sources of contamination, existent data of basement rocks and soil geochemistry in the city as well as public-domain airborne dust were studied. Additionally, a bioaccessibility assay of airborne dust was conducted and the chemical daily intake and hazard index were calculated to provide a preliminary health risk assessment in the vicinity of the port. The main conclusions indicate that the concentrations of Ba, Co, Cr, Mn, Ni, and V recorded from Antofagasta dust likely originate from intrusive, volcanic, metamorphic rocks, dikes, or soil within the city. However, the elevated concentrations of As, Cd, Cu, Mo, Pb, and Zn do not originate from these geologic outcrops, and are thus considered anthropogenic contaminants. The average concentrations of As, Cu, and Zn are possibly the highest in recorded street dust worldwide at 239, 10,821, and 11,869 mg kg−1, respectively. Furthermore, the contaminants As, Pb, and Cu exhibit the highest bioaccessibilities and preliminary health risk indices show that As and Cu contribute to elevated health risks in exposed children and adults chronically exposed to dust in Antofagasta, whereas Pb is considered harmful at any concentration. Therefore, an increased environmental awareness and greater protective measures are necessary in Antofagasta and possibly other similar mining port cities in developing countries.

Effects of mining on the molybdenum absorption and translocation of plants in the Luanchuan molybdenum mine

“…Boojar & Tavakkoli (2011) demonstrated that Mo mining has resulted in a massive increase Mo concentration of soil and the mean concentration of Mo in the mining soil reached 448 mg kg −1 . Similar results have been reported in other studies (Battogtokh, Lee & Woo, 2014;Tapia et al, 2018;Pipoyan et al, 2019). Further, Wang & Tian (2000) has confirmed that the associated heavy metal minerals with Mo in the Luanchuan molybdenum ore mainly include Cu, Mn and Zn.…”

Hacia la utopía concreta: crítica y prospección para la Ciudad Puerto de Antofagasta, Chile

“…El Colegio Médico de Chile ha solicitado reiteradamente que Antofagasta se declare zona saturada por contaminación, cuyo presidente regional, Dr. Aliro Bolados, planteaba en 2015: "Acá no sirven las mejoras, sino que eliminar definitivamente todas las fuentes de contaminación, como única solución para proteger la salud de la población" (Bolados, 2015). Un grupo de científicos de la Universidad de Antofagasta publicaron en la prestigiosa revista PeerJ un robusto conjunto de datos sobre la presencia de metales pesados en el centro histórico de la ciudad de Antofagasta, indicando que dichos contaminantes son producto de actividades humanas y que el principal foco sería el puerto de Antofagasta (Tapia et al 2018).…”

“…En este caso, la propuesta surge desde la urgencia de haber detectado en las actividades del puerto de Antofagasta la principal causa de la alta presencia de metales pesados en el centro de la ciudad. Sin más, se ha catalogado a Antofagasta como la ciudad con mayores niveles de concentración de Cobre, Arsénico, Zinc y Molibdeno a nivel mundial (Tapia, Orrego, Valde, Tchernitchin, Dorador, Bolados & Harrod, 2018).…”

“…Para elaborar la hipótesis de transformación se revisan diversas propuestas proyectuales que se han realizado sobre este elemento urbano para -a partir de esas ideas que no se materializaron-, proponer una utopía concreta que abra un debate disciplinar. Como se ha expuesto, el puerto de Antofagasta tiene ya demostrada una nociva relación ambiental actual con la ciudad, dada su localización fundacional junto al centro histórico de la ciudad y la contaminación que ha emanado desde sus actividades (Tapia et al, 2018), principalmente por metales pesados, la que ha terminado afectando a los niños y habitantes de la ciudad (Colegio Médico de Chile, 2018). No obstante, exploraciones espaciales para su transformación son escasas.…”

Health Risk Due to Heavy Metal(loid)s Exposure Through Fine Particulate Matter and Sedimented Dust in People Living Next to a Beach Contaminated by Mine Tailings

“…Chile is recognized worldwide because much of its economy is based on the mining activity, especially the exploitation of copper deposits, which are concentrated in the north of the country. This has not only meant economic benefits, but also has had serious environmental effects due to air pollution, and contamination of water, soils and marine areas (Carkovic et al 2016, Tapia et al 2018. The city of Chañaral is located in the coast of the Atacama region.…”