Environmental and Public Health Impacts of Mining Tailings in Chañaral, Chile: A Narrative Case-Based Review

Abstract

This narrative case-based review describes the environmental and public health impacts in Chañaral, a town in northern Chile affected by the accumulation of copper mining tailings for the past 80 years. The review included 34 scientific articles published between 1978 and 2025. The keywords used were “mining tailings” and “Chañaral”, without year limits, and covering disciplines such as ecology, public health, environmental history, and territorial studies. The scientific evidence demonstrates the negative impacts on the ecosystem and the human population exposed to toxic metals and arsenic. Geomorphological and biogeochemical alterations have been found on the Chañaral coast, affecting marine biodiversity and water quality. In addition, epidemiological studies indicate exposure to toxic metals measured in street dust and urine, raising concerns on respiratory health in children and metabolic conditions in adults. According to the social sciences, the lack of environmental monitoring and human exposure data contributes to the high health risk perception in the population, posing the need to strengthen environmental monitoring, raise awareness on the risks of exposure to toxic metals, and promote mitigation and restoration strategies. These measures will contribute to sustainable conditions for the Chañaral community through the improvement of comprehensive public policies.

1. Introduction

Mining represents one of the largest volumetric waste streams in the world [1], where less than 1% of the extracted ore is economically relevant, and the remaining fraction is considered waste. Such waste can cause serious damage to the ecosystem and place human health at risk due to toxic metal contamination [2,3,4], in addition to tailings dam incidents. Case reports in the Americas include countries such as the United States (US) (98 cases from 1910 to 1999 and 17 cases between 2000 and 2020), Canada (19 cases before 2000 and 11 cases after 2000), and Chile (32 cases before 2000 and 9 cases after 2000). Regarding global-scale impact, tailings dam incidents from copper mines have been the most frequent (n = 86), mostly originating from Chile (n = 35), mainly due to earthquakes. Chile, the US, Peru and the Philippines account for roughly 77% of all cases of copper mine failure. During the study period (1915–2020), the countries reporting the highest numbers of human deaths were China (n = 516), Bulgaria (n = 488), Brazil (n = 331), Mexico (n = 306), Italy (n = 269), and Chile (n = 258) [5].

Chile stands out as one of the world’s leading copper producers. In 2022, copper production accounted for 10.9% of the country’s Gross Domestic Product (GDP) [6]. Despite its economic relevance, the boom in mega-mining has led to interventions in mining territories with limited surveillance on environmental and human impacts. Insufficient surveillance and regulation over the past decades have generated various consequences, such as the presence of mining tailings and environmental liabilities, which constitute a permanent risk for nearby populations, such as in the municipality of Chañaral [7].

In this sense, socio-environmental inequality, also called environmental injustice, occurs when territorial, national, or regional development, driven by economic ventures or public policy actions or inactions, exposes parts of the population to disproportionate environmental risks. Additionally, it includes situations where access to natural resources in areas inhabited and worked in by local populations is restricted, infringing upon numerous human rights such as the right to a clean environment, safe living and working conditions, and the enjoyment of cultural practices [8]. This form of injustice arises from a societal disregard for the value, autonomy, and territory of affected communities, manifesting in various ways. These include economic valuations that prioritize profit over well-being, biased environmental regulations, limited participation opportunities for impacted communities, the exclusion of local economic practices, surveillance gaps in institutional monitoring, inadequacies in health services, and biases in research on environmental and health issues across time [8].

Environmental issues and the effects on inhabitants’ health in Chañaral have been addressed by a wide range of professionals, from ecology and geochemistry to public health experts, generating evidence on socio-environmental issues. However, this evidence has not been considered in urban planning to promote sustainable development that protects the life and health of the population in the territory. Therefore, the purpose of this article is to analyze the scientific evidence on the environmental, social, and health impacts of exposure to toxic metals from mining tailings in the city of Chañaral. This research will contribute elements for a debate on public environmental, health, and urban planning policies that address the socio-environmental problem of Chañaral, taking into consideration the fact that Chañaral is identified as a “potential sacrifice zone” according to the Human Rights Council, United Nations [9].

2. Materials and Methods

2.1. Study Area

Chañaral is a small coastal city located in the Atacama region, 167 km northwest of Copiapó (regional capital) and 963 km north of Santiago, Chile (national capital) (Figure 1). According to the 2017 census, Chañaral housed 12,219 inhabitants [10]. Of these, 11,705 inhabitants were registered in the state health service (National Health Fund, FONASA) (95.8% of the total population). The main economic activities are metal manufacturing and the exploitation of mines and quarries, which represent 10.5% and 42% of the city’s economic activity, respectively [10]. This is consistent with the regional situation, as the mining industry is the basis of the economy in the Atacama region, representing 48% of the region’s Gross National Product (GNP) [11]. In Chañaral, 10 million tons of tailings and a similar amount of sterile waste were produced in 2017 by Codelco’s Salvador Division [12], which is the main economic actor.

Mining activity and the problems associated with waste and tailings are not recent. Since the mid-20th century, the population of Chañaral has been exposed to mining tailings dumped into the Salado River by the Potrerillos and El Salvador mines, managed by the US company Andes Copper Mining Company and, since 1970, by the state-owned Codelco Chile. It is estimated that between 1938 and 1990, more than 300 million tons of toxic waste, containing arsenic, lead, and other toxic metals, as well as approximately 850 million tons of sewage, were deposited in the Chañaral Bay [15]. The tailings dam exceeded its capacity in 1938, so the mine tailings were initially discharged into the “Los Patos” estuary and subsequently dumped into the bay [15].

For more than three decades, tailings were uninterruptedly deposited on the coast of Chañaral until the Ministry of Public Works diverted their dumping towards the area of Caleta Palito, 12 km north of Chañaral (Figure 1, letter b) in 1974 through canalization to “avoid the progressive sand banking of the bay of Chañaral and the consequent disablement of its port facilities” [16]. All these deposits with more than 300 metric tons of copper tailings [17] caused the modification of the coastline, so that today a large part of the area used as a beach is mostly made up of mining tailings deposits (Figure 1). These tailings have generated serious environmental problems due to their repercussions on the terrestrial and marine environment, as well as on people’s health [18].

Mining activity has also influenced the development of Chañaral. Since the first half of the 20th century, copper mining and port activity have played a key role in the development of the municipality’s urban infrastructure. Although the unsafe disposal of mining tailings exposes the population to serious health risks, the urban fabric continued to grow to the north and south of Route 5 due to the gradual increase in population. By 1980, the population had increased to 7000 inhabitants and, by 2011, it expanded further south with an additional 3000 inhabitants, reaching as far as the Chañaral aerodrome (Figure 1) [19]. According to the 2017 census, 90.07% of the municipality’s population resides in urban areas [7], mainly highlighting the urban area of Chañaral and, to a lesser extent, the locality of Barquito. This expansion poses challenges such as the lack of space for housing and the need to expand urbanization coverage. In addition, no remediation work has been carried out, maintaining the presence of toxic substances in an urbanized area [20].

2.2. Methods

A narrative review of the scientific literature on toxic metal cases in Chañaral was conducted using databases such as PubMed, Scopus, Web of Science, and Jstor. The time frame was between the years 1978 and 2025.

Inclusion criteria comprised peer-reviewed articles in Spanish and English in indexed journals. Scientific research articles, technical reports, and dissertations were included.

A total of 34 articles were selected from indexed journals published between 1978 and 2022 and analyzed. The keywords used were Chañaral, tailings, metal exposure, metal contamination of soils, particulate matter exposure effects, seaweed, and health effects. Each article was given an identification code to facilitate systematization and organization. The first step toward organization involved major themes of scientific production, that is, environmental, health, and social research, following a chronological order. Through a descriptive analysis, the content of the publications was categorized according to study population, methodological approach, the toxic metals involved, and scientific evidence. In addition, using the same methodological strategy, several postgraduate research studies in the fields of public health, law and urban studies were identified and are presented as Supplementary Materials (Table S1), classified into studies with online access and those without online access.

3. Results

Considering a timeline spanning 1978 through 2025, different types of research were conducted in Chañaral, Chile. The results were categorized by decades, marking significant events and corresponding studies. In the period 1922–1980, events such as the “1922 earthquake/tsunami” and “1972 debris flows” prompted primarily environmental studies, including geomorphological impacts (1978), and biological degradation in vegetation, invertebrates, and birds (1980). After 2010, a shift toward integrated studies emerged as the methodology diversified, featuring social studies (2010, 2011, 2022), including citizen mobilization against mining (2022); atmospheric environmental assessments (2012, 2013, 2014); and epidemiological studies (2016, 2018), covering toxic metals in humans and metabolic conditions in adults. Finally, socio-environmental research, integrating disciplines, covered the period 2021–2025. Interestingly, debris flows reappeared in 2015 and 2017, highlighting their critical role in cumulative environmental degradation. The results of this case-based review of the scientific literature on the environmental, health, and social impacts of the presence of mining tailings are classified by thematic issues and chronological order.

3.1. Environmental Impacts

The interest in determining the environmental consequences of tailings deposition in the Chañaral Bay has involved the participation of a variety of experts, including ecologists, geochemists, chemical engineers, and biologists (Table 1). The first studies were carried out in the 1970s to investigate the geomorphological impact and identify the mechanisms of contamination and their interactions on the seabed. There is now strong scientific evidence showing how mining activity and the release of toxic metals affect marine sediment composition, biological communities, and water quality in this bay.

Studies carried out by Castilla and Nealler [21] revealed that the low light penetrability values in Chañaral Bay are due to the presence of accumulated sediments. On the other hand, Dold [22] and Lee and Correa [23] (2006) point out that seawater is mainly affected by As, Mo, Cu, and Zn contamination through infiltration and colloidal transport from tailings and the Rio Salado.

Similarly, Andrade et al. [24] concluded that the highest concentrations of Cu, both as solid particles and dissolved in water, are found in sediments from mining activities that have been agitated or suspended in the water column. Lee et al. [25] found high concentrations of metals in interstitial water, indicating the possible presence of contaminants that may affect aquatic organisms. This underlines the importance of taking into account microbial activity and sedimentation processes in the dynamics of contaminants in the aquatic environment.

Since the late 1990s, several studies have provided valuable evidence on the biological effects of metals from mining tailings on the diversity and abundance of species present in Chañaral Bay, such as algae and birds [26,27]. These studies indicate that adult and juvenile Lessonia nigrescens algae can show normal growth and regeneration even in the presence of relatively high levels of copper in the water (150 μg L⁻¹) [26,28]. However, some minor effects on growth may be present. Such data could be used as a detoxification strategy, as algae may contribute to metal attenuation through their uptake and accumulation [29]. Such a procedure could be implemented as part of a tool for the ecological restoration of Chañaral Bay.

Likewise, parallel studies carried out by Medina et al. [30] determined that dissolved copper at levels of 8.72–25.74 μg/L, affects the diversity of sessile organisms (organisms that do not move from their location), suggesting that the presence of copper in water may have negative implications on the community of organisms fixed or attached to the substrate. De la Iglesia et al. [31] also highlighted that the presence of copper has a strong effect (statistically significant R-value 0.49) on the structure of epilithic bacterial communities, but that this effect is reversible and returns to its original state after 48 h of copper removal. These results show how metals can have an impact on biological communities but also indicate that some effects may be temporary and mitigable.

Studies carried out by Fariña and Castilla [32] indicate that the low diversity and abundance of algae at present are strongly influenced by herbivory, but the chronic effects of contaminant discharges cannot be ruled out as a possible factor that also affects the diversity and abundance of algae. All these studies highlight the importance of understanding the combined effects of herbivory and copper contamination in the marine ecosystem of Chañaral Bay. The interaction of these factors may have implications for the biological diversity and stability of marine habitats in the impacted area.

In the case of birds, Valladares et al. [27] found an accumulation of cadmium in their kidneys, at concentrations of 1.05 μg/g (range 0.044 to 9.86 μg/g), values considered within the normal range, suggesting a possible effect by this metal. Although lead concentration levels were considered normal and no significant effects were found, there is evidence that cadmium may be negatively affecting these birds compared to others with a similar ecological role. Therefore, these findings show that the presence of copper and other contaminating metals can have negative effects on biological communities, both in algae and birds. In addition, bacterial communities can also be affected by the presence of copper, although its impact appears to be temporary and reversible. Such biological effects are important considerations for the conservation and management of the marine environment of Chañaral Bay.

Table 1. Studies on adaptation and ecological alteration due to exposure to toxic metals, Chañaral Bay, Chile (1978–2025).

ID	Year	Authors	Population/Matrix	Pollutant(s)	Method	Reported Evidence	Ref.
1	1978	Castilla, J. and Nealler, E.	Sub-littoral organisms	Not applicable	Observations and samplings	Low values of light penetrability reflected	[21]
2	1983	Castilla, J.C.	Marine invertebrates	Molybdenite and chalcopyrite	Sandy beach morphometric and sediment analysis	Geomorphological coastal modifications	[33]
3	1997	Riquelme, C, et al.	Green algae Enteromorpha compressa	Cu	Laboratory incubation and isolation of epiphyte bacteria	High copper tolerance of epiphytic bacteria	[34]
4	1998	Correa, J.A. et al.	Algae Lessonia nigrescens	Cu	Three alternative hypotheses were tested on copper tolerance	Sea water mixed with affluent was not lethal to algae	[26]
5	1999	Correa, J.A. et al.	Algae Enteromorpha compressa	Cu	Monitoring macroalgae, sessile, and mobile invertebrates	Low algae diversity influenced by herbivory	[28]
6	2001	Lee, M.R. et al.	Nematode, copepod	Trace metals	Laboratory analysis	Extent of metal impacts on meiofauna densities	[35]
7	2001	Fariña, J.M. and Castilla, J.C.	Seawater	Cu, Zn, Cd, inorganic particles	Standard methods designed	Variation in sessile species in rocky intertidal benthic communities	[32]
8	2002	Lee, M.R. et al.	Cores of porewater samples	Cu, Al, As, Cr, Mn, Ni, Zn	Diffusive gradients in thin-film (DGT) techniques	High concentrations of metals in porewater	[25]
9	2005	Medina, M. et al.	Algae and sessile invertebrates	Cu	Measurement of total dissolved copper concentration	Dissolved copper affects the diversity of sessile organisms	[30]
10	2005	Ramírez, M. et al.	Sessile species	Cd, Cu, Fe, Mn, Ni, Pb, Zn	Sequential chemical extraction method	Mining activity leads to the presence of copper	[36]
11	2005	Lee, M.R. and Correa, J.A.	Meiofaunal assemblages	Cu	Diffusion gel technique (DGT)	Copper found in seawater is connected to mining tailings	[37]
12	2006	Correa, J.A. et al.	Kelp Lessonia nigrescens (Phaeophyceae)	Not applicable	Experimental transplants of the large kelp Lessonia nigrescens (Phaeophyceae)	Transplanted plants regenerated	[38]
13	2006	Dold, B.	Tailing deposits	Cu, Ni, Zn, Pb, Mo, As	Measurement of parameters in the tailings deposit	The sea is affected by As, Mo, Cu, and Zn contamination. The population of Chañaral is mainly exposed to high concentrations of Cu and minor concentrations of Ni and Zn	[22]
14	2006	Andrade, S. et al.	Intertidal ecosystem	Cu	Total dissolved copper concentration was determined by ASV	Resuspended mine-derived sediments have the highest value of particulate and dissolved copper	[24]
15	2010	Bea, S.A. et al.	Efflorescent salt in coastal mine tailing deposits	Halite (NaCl) and eriochalcite (CuCl2·2H2O)	Reactive transport modeling	The reduction in evaporation is a key factor that prevents the formation of salt deposits and a specific mineral (eriochalcite)	[39]
16	2012	De la Iglesia et al.	Epilithic intertidal bacterial	Cu	Culture-independent molecular approach, field sampling, and laboratory microcosm experiments	Copper significantly affects bacterial communities, but its impact can be temporary and reversible	[31]
17	2012	Ramos-Jiliberto, R. et al.	Intertidal community	Cu	Retrospective qualitative analysis of ecological networks	Four initiators were identified as the primary drivers of observed community structure changes in the intertidal system	[40]
18	2012	Koski, R.	Mining activities in Spain (Gulf of Cádiz, Portman Bay), Chile (Chañaral Bay), the Philippines (Marinduque Island), and the United States (Callahan mine, Maine; Ellamar and Beatson mines, Prince William Sound, Alaska)	Cu, Pb, Zn	The dispersal of metals is described along a series of pathways leading from source rocks to the marine biosphere	The pathway approach considers a number of physical and chemical processes that influence the dispersion of metals in the continuum from the metal source to bioreceptor	[41]
19	2013	Valladares, P. et al.	Wild turkey vulture, Cathartes aura	Cd, Pb	Analysis of Cd and Pb using an atomic absorption spectrophotometer and an autosampler	High cadmium accumulation in the kidney compared to similar birds	[27]
20	2013	Korehi H et al.	Microorganisms	Cu	Scanning electron microscopy	Extreme mine tailings provide an environment that supports the growth of prokaryotes	[42]
21	2014	Besaury L et al.	Archaeal and bacterial communities	Cu	Molecular tools such as the 16S rRNA gene Q-PCR and RT-Q-PCR	Bacteria are the dominant group within the prokaryotic community	[43]
22	2018	Bonnail E et al.	Water fog composition	Cu, As	Fog water collectors. Volumes oscillate between 0 and 9000 L per month	High acidity and high concentrations of Cu and As in water collected on top of the mountain were found	[44]

Table 1. Studies on adaptation and ecological alteration due to exposure to toxic metals, Chañaral Bay, Chile (1978–2025).

ID	Year	Authors	Population/Matrix	Pollutant(s)	Method	Reported Evidence	Ref.
1	1978	Castilla, J. and Nealler, E.	Sub-littoral organisms	Not applicable	Observations and samplings	Low values of light penetrability reflected	[21]
2	1983	Castilla, J.C.	Marine invertebrates	Molybdenite and chalcopyrite	Sandy beach morphometric and sediment analysis	Geomorphological coastal modifications	[33]
3	1997	Riquelme, C, et al.	Green algae Enteromorpha compressa	Cu	Laboratory incubation and isolation of epiphyte bacteria	High copper tolerance of epiphytic bacteria	[34]
4	1998	Correa, J.A. et al.	Algae Lessonia nigrescens	Cu	Three alternative hypotheses were tested on copper tolerance	Sea water mixed with affluent was not lethal to algae	[26]
5	1999	Correa, J.A. et al.	Algae Enteromorpha compressa	Cu	Monitoring macroalgae, sessile, and mobile invertebrates	Low algae diversity influenced by herbivory	[28]
6	2001	Lee, M.R. et al.	Nematode, copepod	Trace metals	Laboratory analysis	Extent of metal impacts on meiofauna densities	[35]
7	2001	Fariña, J.M. and Castilla, J.C.	Seawater	Cu, Zn, Cd, inorganic particles	Standard methods designed	Variation in sessile species in rocky intertidal benthic communities	[32]
8	2002	Lee, M.R. et al.	Cores of porewater samples	Cu, Al, As, Cr, Mn, Ni, Zn	Diffusive gradients in thin-film (DGT) techniques	High concentrations of metals in porewater	[25]
9	2005	Medina, M. et al.	Algae and sessile invertebrates	Cu	Measurement of total dissolved copper concentration	Dissolved copper affects the diversity of sessile organisms	[30]
10	2005	Ramírez, M. et al.	Sessile species	Cd, Cu, Fe, Mn, Ni, Pb, Zn	Sequential chemical extraction method	Mining activity leads to the presence of copper	[36]
11	2005	Lee, M.R. and Correa, J.A.	Meiofaunal assemblages	Cu	Diffusion gel technique (DGT)	Copper found in seawater is connected to mining tailings	[37]
12	2006	Correa, J.A. et al.	Kelp Lessonia nigrescens (Phaeophyceae)	Not applicable	Experimental transplants of the large kelp Lessonia nigrescens (Phaeophyceae)	Transplanted plants regenerated	[38]
13	2006	Dold, B.	Tailing deposits	Cu, Ni, Zn, Pb, Mo, As	Measurement of parameters in the tailings deposit	The sea is affected by As, Mo, Cu, and Zn contamination. The population of Chañaral is mainly exposed to high concentrations of Cu and minor concentrations of Ni and Zn	[22]
14	2006	Andrade, S. et al.	Intertidal ecosystem	Cu	Total dissolved copper concentration was determined by ASV	Resuspended mine-derived sediments have the highest value of particulate and dissolved copper	[24]
15	2010	Bea, S.A. et al.	Efflorescent salt in coastal mine tailing deposits	Halite (NaCl) and eriochalcite (CuCl2·2H2O)	Reactive transport modeling	The reduction in evaporation is a key factor that prevents the formation of salt deposits and a specific mineral (eriochalcite)	[39]
16	2012	De la Iglesia et al.	Epilithic intertidal bacterial	Cu	Culture-independent molecular approach, field sampling, and laboratory microcosm experiments	Copper significantly affects bacterial communities, but its impact can be temporary and reversible	[31]
17	2012	Ramos-Jiliberto, R. et al.	Intertidal community	Cu	Retrospective qualitative analysis of ecological networks	Four initiators were identified as the primary drivers of observed community structure changes in the intertidal system	[40]
18	2012	Koski, R.	Mining activities in Spain (Gulf of Cádiz, Portman Bay), Chile (Chañaral Bay), the Philippines (Marinduque Island), and the United States (Callahan mine, Maine; Ellamar and Beatson mines, Prince William Sound, Alaska)	Cu, Pb, Zn	The dispersal of metals is described along a series of pathways leading from source rocks to the marine biosphere	The pathway approach considers a number of physical and chemical processes that influence the dispersion of metals in the continuum from the metal source to bioreceptor	[41]
19	2013	Valladares, P. et al.	Wild turkey vulture, Cathartes aura	Cd, Pb	Analysis of Cd and Pb using an atomic absorption spectrophotometer and an autosampler	High cadmium accumulation in the kidney compared to similar birds	[27]
20	2013	Korehi H et al.	Microorganisms	Cu	Scanning electron microscopy	Extreme mine tailings provide an environment that supports the growth of prokaryotes	[42]
21	2014	Besaury L et al.	Archaeal and bacterial communities	Cu	Molecular tools such as the 16S rRNA gene Q-PCR and RT-Q-PCR	Bacteria are the dominant group within the prokaryotic community	[43]
22	2018	Bonnail E et al.	Water fog composition	Cu, As	Fog water collectors. Volumes oscillate between 0 and 9000 L per month	High acidity and high concentrations of Cu and As in water collected on top of the mountain were found	[44]

3.2. Impacts on Human Health (Exposure and Damage)

Research has established an association between the aeolian action of particulate matter from mining tailings deposited in the Chañaral Bay and adverse health effects on the surrounding populations. Korehi et al. [42] provide evidence of how microbial activity in extreme mining waste contributes to the release of acid and metals into water and air, which can lead to atmospheric contamination in areas near mining deposits. Together with the studies of Dold [22], a general context of exposure to metal-enriched air-toxic metals in the marine environment of the bay was formed, revealing possible impacts through both aquatic and atmospheric routes.

In the field of population health, a quantitative approach was used to establish the presence of metals in urine and blood samples and changes in lung function in residents of Chañaral (

Table 2. Studies on evidence of exposure and health effects in Chañaral Bay, Chile (1978–2025).

ID	Year	Authors	Population (Sample)	Pollutant(s)	Method	Reported Evidence	Ref.
23	2016	Cortés, S et al.	Adults 18 to 65 years old. Sample: 205 individuals	Cu, Hg, Ni, Pb, As	A questionnaire and a urine sample	The study revealed elevated urinary levels of total and inorganic arsenic and lead in this area, surpassing international standards. These levels were higher than those in other regions of Chile, indicating potential environmental health concerns for the population.	[45]
24	2018	Mesías Monsalve, S. et al.	School spaces. Sample: 10 schools	Na, Cl, S, Ca, Fe, K, Mn, Ti, Si, MP2.5	Trace element concentrations were measured using X-ray fluorescence on two consecutive days in both summer and winter of 2012 and 2013	Indoor school spaces, particularly classrooms, had higher trace element levels compared to outdoor environments. The most abundant elements detected were Na, Cl, S, Ca, Fe, K, Mn, Ti, and Si, associated with the Earth’s crust.	[46]
25	2019	Moya, P.M. et al.	Sample of 158 participants, 18 to 65 years old	As, Cu, Ni, Pb, Mn	Cross-sectional epidemiological study	High concentrations of arsenic and copper were found in street dust; arsenic concentration in street dust was correlated with the distance to the mine tailings; urinary levels of metals were low and did not significantly correlate with the socioeconomic level (SES) of the population; there was no clear relationship between SES and urinary levels of metals.	[47]
26	2021	Cortés S et al.	Sample: 25 volunteers, 45 to 65 years old	As and its metabolites, Cu, Ni, Cr, and Pb	Cross-sectional study. Inductively coupled plasma mass spectrometry (ICP-MS) to measure metals. Questionnaire for demographic, lifestyle, metal exposure, and health status	Urinary Ni levels are positively linked to glycemia and IL-6. AsBet levels are positively linked to total cholesterol, while inorganic arsenic is linked to glycemia. A negative association was found between AsBet and 8-OHdG.	[48]
27	2021	Cortés S et al.	Adults no Sample: 205	Cu, Hg, Ni, Pb, As	Questionnaire about health risk perception of environmental hazards	The final questionnaire is a straightforward, reliable, and valuable tool for assessing environmental health risk perceptions in Latin American countries. Environmental health risk perception is higher in women.	[49]

) [45,46,47,48,49].

Cortés et al. [45] found that the levels of total arsenic, inorganic arsenic, nickel, copper, mercury, and lead in the urine of people in this area exceeded the values found in other regions of Chile and international measurements. The high percentages of people with detectable levels of each metal suggest the recent contact of a significant part of the population with these metals, and potential long-term damage, especially from simultaneous exposure to these metals.

Monsalve et al. [46] also identified high levels of trace elements in the air (PM2.5) and soil (Na, Cl, S, Ca, Fe, K, Mn, Ti, and Si) from indoor spaces of schools (n = 10), especially in classrooms, compared to outdoor environments. The most abundant elements found in school dust are associated with the Earth’s crust. This indicates possible indoor air pollution in schools, which may have implications for the health of students and staff.

Similar results were found by Moya et al. [47], who highlight the presence of arsenic, nickel, and copper levels in the urine of people living near the tailings in the bay. The authors also argue that there is contamination of the urban environment due to high levels of copper and arsenic found in street dust near the tailings. Identifying differences in environmental exposure according to socioeconomic status within Chañaral suggests that different population groups may be exposed to different levels of contamination.

Cortés et al. [48] describe how urinary metal exposure levels are related to metabolic alterations. In particular, urinary nickel levels are directly associated with significant increases in total cholesterol, while increases in inorganic arsenic levels are associated with increases in glycemia.

There is an additional study on the perception of environmental risks and their consequences on health, which has shown the usefulness of quantitative instruments for this purpose. In general terms, the people of Chañaral show a high perception of health risks associated with the characteristics of the environment and exposure to chemical agents [49].

These results are in agreement with the notion that people living near the mine tailings in Chañaral Bay are exposed to toxic metals, which can have chronic detrimental effects on respiratory and cardiovascular health in adults and children. The presence of high levels of metals in urine and street dust, as well as the differences in exposure according to socioeconomic level, emphasizes the importance of taking measures to reduce contamination and protect the health of the population near the mine tailings in Chañaral Bay due to the exposure scenario described above.

3.3. Analysis from the Social Sciences

In the social sciences, studies carried out by Vergara [15], González [20,50,51], Schorr [52], Aedo [53], and Quintana [54] share a common interest in addressing the pollution and environmental impact caused by large-scale copper mining in Chañaral, from a historical and socio-environmental perspective (

Table 3. Studies on the social evidence and historical reconstruction of impact and citizen mobilization in Chañaral Bay, Chile (1978–2025).

ID	Year	Reference	Subject of Study	Social Group	Method	Reported Evidence	Ref.
28	2011	Vergara, A.	Impact of large copper mining in the Province of Chañaral between 1938 and 1990	Not applicable	Reconstruction of environmental history through documentary consultation	The disposal of tailings into the riverbed and sea has changed the coastline, devastated bay plants and marine life, and impacted the health of local residents	[15]
29	2018	Schorr, B.	Analysis of the environmental conflict in Chañaral and the population’s opposition to mining	Environmental activists and mining companies	Documentary consultation	Activists in Chañaral struggle to gain support in holding the mining company accountable and seeking compensation for the damage caused	[52]
30	2018	González, P.	Study of the background of the environmental problem at Chañaral until the legalization and termination of tailings disposal in 1990	Mining companies and population	Documentary consultation	Failed solutions and unsuccessful projects demonstrate socio-ecological inequalities, worsening the environmental impact, and leading to urban lethargy in Chañaral	[20]
31	2019	González, P.	Territorial production in the coastal town of Chañaral; changes were promoted since the 1920s	Mining companies and population	Analysis of written, oral, and cartographic sources	Contamination remains a significant concern, creating a physical and symbolic burden and adversely affecting urban quality of life. Hence, the socio-environmental conflict endures in a state of latency	[50]
32	2019	Aedo, M.	The affections and knowledge of women leaders in Chañaral regarding the search for justice and reparation of the territory	Women leaders of social organizations	Interviews	Due to the denial of justice and reparations by governments, women have established support systems encompassing health, food, child and elderly care, as well as education. These systems aim to repair the damage caused by coming together, uplifting their community’s spirits, and creating spaces for enjoyment and connection	[53]
33	2021	González, P.	The socio-environmental situation of Chañaral as an environmental, biomedical and sociocultural phenomenon	Mining companies and population	Analysis of qualitative information and reports on public health	Daily suffering and uncertainties about toxic risks create environmental distress due to the lack of comprehensive measures to address the issue effectively	[51]
34	2022	Quintana-Muñoz, J.	Analysis of territory meanings	Mining companies and population	Interviews and speech analysis	The population demands the right to stay in a safe territory and shape it according to their needs	[54]

). These investigations explore diverse topics, such as mitigation measures, community resistance, and socio-cultural aspects related to environmental suffering. In addition, they employ a variety of methodologies, including historical analysis, qualitative approaches and case studies, combining written sources, interviews, and public health data. Through their findings, they highlight the importance of approaching the environmental problem from multiple perspectives to better understand its complexity and to find effective solutions.

For example, Vergara [15] reconstructs the history of mining tailings dumped into the Salado River and the Pacific Ocean by mining companies between 1938 and 1990. He also highlights the lack of action by the authorities and how local inhabitants denounced the contamination early on. Following the same line of analysis from environmental history, González [20] reviews the environmental problems of Chañaral up to 1990. He aims to explain the socio-ecological inequality and how mitigation measures have been ineffective, leading to urban lethargy and latent conflict in the collective memory of the inhabitants. For his part, Gonzalez’s [50] argument consists of the analysis of the territorial production of the coastal town of Chañaral and the changes caused by large-scale copper exploitation. In his opinion, the actors in dispute within the community take different positions, which complicates the analysis regarding the opposition between the company and the affected community.

Studies by Schorr [52], Aedo [53], and González [51] address the impact of pollution on the daily lives of the inhabitants of Chañaral. Schorr [52] highlights that many inhabitants have naturalized pollution and consider it an intrinsic part of their lives, which could affect their participation in protests and mobilizations against the mining companies responsible for the pollution. On the other hand, Aedo [53] highlights the strength of resistance in Chañaral, focusing on the emotional experiences and responses of the community, particularly women leaders. Her study is based on environmental suffering and highlights the importance of female resistance against contamination, positioning women as key actors in the search for justice and reparation for the territory affected by mining. In this sense, Aedo [53] provides a deeper and more detailed look at the experiences of women in the community.

Quintana [54] explores the meanings that the population gives to the territory from an emotional dimension and sets out to understand how people have built a territorial demand based on the “right to stay in a safe territory” and the “right to make territory”. Through a qualitative interpretative–hermeneutic methodology, Quintana focuses on the construction of meaning in the social world, analyzing emotions, and exploring the feelings and meanings associated with the territory of Chañaral.

González [51] also analyzes environmental suffering in Chañaral, relating it to uncertainty about toxic risk and the lack of concrete measures available to address the problem. His approach focuses on the complex relationship between the daily experiences of the inhabitants, the incidence of biomedical knowledge on the scientific legitimacy of the environmental problem, and the need to consider sociocultural aspects in the urban-environmental planning of territories affected by contamination.

These studies show that interdisciplinary research is essential to comprehensively address Chañaral’s socio-environmental problem and to find solutions that protect the health of the population and restore the quality of the environment. Only through a joint effort in which the voices of the community are heard and the complex socio-environmental dynamic is considered, is it possible to achieve a significant change in the current situation and guarantee a sustainable future for Chañaral and its inhabitants.

4. Discussion

Evidence on the environmental, ecological, and public health impacts in Chañaral, as a result of the dispersion of mining tailings along the bay, has led to a scenario of socio-environmental inequality that embodies what Gouveia et al. [55] describe as environmental injustice. From the environmental sciences, there is valuable scientific evidence that shows that the accumulation of tailings has caused an alteration of the geomorphology and biogeochemical dynamics of the coast, as well as the retreat of the sea and solidification of the bay (Table 1). In terms of public health, it is reported that people are directly impacted by the particulate matter (PM) lifted by wind action, transporting metal-rich particles to the city of Chañaral in the absence of containment measures. This leads to clear exposure to toxic metals, as evidenced by biomonitoring studies, and respiratory and metabolic alterations, which require further investigation (Table 2). In the social sciences, studies have highlighted the importance of approaching the environmental problem from different perspectives, exploring mitigation measures, community resilience, and socio-cultural aspects related to environmental suffering. Research has highlighted the need to understand the emotional and affective connections that people establish within the territory and how these perceptions influence their perception of the inhabited space (Table 3). Similar findings were reported by Cacciuttolo et al. (2023) [17], who concluded that mine tailings are potentially toxic to both communities and the environment, posing a considerable health risk, and cannot be considered as inert and innocuous materials. They reported chemical compounds present in copper mine tailings, including metals such as copper, manganese, vanadium, metalloids, such as As, and other non-metals such as chlorides and sulfates, as also reported by Dold (2006) [22].

In the Chañaral Case, health risk factors for humans are linked to the water and contaminant-containing acid rock drainages; to the soil, due potential instability underlied by seismic events; and to the alteration of the soil’s chemical quality due to mine tailings and land use [17]. Additionally, air exposure is related to the generation of dust enriched in toxic metals [22]. Our analysis supported the findings that changes in the quality of soil, water, the atmosphere, and locally-produced food caused by the presence of toxic metals can cause changes in the structure and physiology of living organisms, including human populations in Chañaral. Also, it is interesting that the timeline of the research made in Chañaral reflects a historically grounded, interdisciplinary approach, marked by a gradual integration of physical, biomedical, and social sciences, which highlights direct links between environmental crises and scientific responses, and an evolution from descriptive accounts to human-centered and policy-relevant analysis.

These studies show that pollution in Chañaral is a complex and multidimensional problem that requires a comprehensive and collaborative response. Despite all this scientific evidence, the Chañaral municipality does not have urban plans in place which adequately addresses this problem [51]. This generates an important challenge for its urban sustainability, in which visions must converge between environmental studies, environmental management and urban planning to reduce the health risk to the population. Not addressing this problem in a comprehensive manner deepens the environmental suffering of inhabitants [51,52,53,54].

Therefore, the broad health impacts on children, adults, and the elderly should be taken into consideration when inhabitants are exposed to a mix of toxic metals and metalloids [56]. It is advisable to promote public policies that seek decontamination under appropriate environmental governance criteria and that use scientific knowledge to develop environmental restoration experiences. It is important to include the historical and sociocultural dimensions of pollution in a sustainable development plan and in environmental education programs. This will make it possible to recognize and address the problem in a preventive manner, thus contributing to the health of both humans and the environment, understanding that both entities are intrinsically related. To achieve this, it is necessary to have the collaboration of urban-environmental planners, ecologists, experts in public health and environmental epidemiology, as well as educators and social scientists. These actors must work together to carry out an environmental remediation process that encompasses the different dimensions of pollution.

According to Gouveia et al.’s ([55] concept of environmental justice, defined as “addressing both unequal exposure to environmental hazards and the resulting health disparities” in Chañaral, residents are disproportionately exposed to pollution due to mining activities, which exacerbates public health inequities among the most vulnerable, including children. Thus, the situation reflects environmental injustice by underscoring how industrial waste and socio-ecological inequalities intersect to disproportionately impact the health and environment of these communities. Environmental actions that meet the characteristics mentioned by Porto et al. [8] align with the perspectives of both Gouveia et al. [55] and Villasana et al. [57], who call for structural changes to address the root causes of environmental and health inequalities. While Gouveia et al. stress the need to mitigate unequal exposure and health effects among vulnerable populations, Villasana et al. advocate for a constitutional and political framework that ensures dignity, health, and environmental protection. Together, these approaches support a comprehensive development plan for Chañaral, which can protect both human and environmental health by addressing systemic inequalities and fostering resilience through policies centered on social and environmental equity.

The lack of urban planning that addresses environmental issues in Chañaral reveals a marked disconnect between urban planning policies and public health decisions, both of which are unaligned with the scientific evidence. Although environmental legislation has advanced in Chile over the last 30 years, environmental liabilities are not systematically considered in urban planning. Law No. 19,300 on the General Bases of the Environment, enacted in 1994, specifically determined that urban development projects that generate socio-environmental alterations must declare their impacts through the Environmental Impact Assessment System. Subsequent modifications established the guidelines for Strategic Environmental Assessment (SEA), a mechanism that allows the incorporation of environmental vision into the Territorial Planning Instruments in the early stages of the decision-making process. Specifically, it states that “the environmental factors of sustainable development must be considered during the formulation of public policies and plans of a general normative nature that have an impact on the environment or sustainability”.

Therefore, the SEA is indicated as mandatory for intermunicipal and municipal regulatory plans. In practice, however, these regulations do not have clear commitments at the local level, so the relationship between environmental problems, public health, and urban planning instruments is insufficiently considered [58,59,60,61]. Although Article 2.1.17 of the General Ordinance of Urbanism and Construction (OGUC), enacted in 1992, establishes areas with the presence of contaminants due to anthropogenic activities as “risk zones” [58], the areas where mining tailings are located are not classified as risk zones due to the outdatedness of communal regulatory plans and the lack of relevant soil studies [60,61]. In addition, the closure of mining sites and facilities was only regulated in Chile in 2011 by Law 20,551. The objective of the law is to mitigate the negative effects of the mining industry and to protect the life, health, and safety of people and the environment. However, this law does not have a retroactive effect on previously inactive mining operations. Therefore, Chañaral’s environmental problems would not be regulated or mitigated, since they predate the law.

In addition, this study proposes that it is fundamental to address the socio-environmental inequality in the design and implementation of such policies. Environmental justice implies taking actions based on the acknowledgement of unequal exposure to toxic risks affecting the health, human rights and dignity of communities exposed to the chemical and socio-cultural effects of pollution [8]. Joint work between experts from different disciplines and community participation is essential to find effective solutions that protect the health of the population through planning processes leading to mitigating actions, achieving a significant change in the current situation and guaranteeing a sustainable future for Chañaral and its inhabitants. Decision-making based on scientific evidence and the consideration of social and emotional aspects is key to addressing the challenge of the contamination in this area and promoting the well-being of the population and the environment. Boyd’s report (2024) establishes that “Chile should apply a human rights-based approach to laws, regulations, policies, and actions governing the production, import, sale, use, release, and disposal of substances that may harm human health or the environment, to eliminate the negative impacts on human rights. A rights-based approach should also govern clean-up, remediation, restoration, and compensation. A rights-based approach clarifies the obligations of Governments and the responsibilities of businesses, prioritizes the most disadvantaged, and catalyses ambitious action. Immediate action must be taken to eliminate residents’ exposure to environmental hazards. Putting economic considerations ahead of human rights is a fundamentally flawed form of decision-making, as the Inter-American Commission on Human Rights recently clarified.” [9].

In short, actionable recommendations emerging from different disciplines must consider the following as a minimum [56,62]:

(a)

Remediation and management of mining tailing, integrating environmental, geochemical, and hydraulic aspects. Efforts are required in the control of particulate matter with metals emitted from the tailings.

(b)

Research on toxicity, biodegradability, and bioaccumulation in biota and living organisms. It may be necessary to evaluate phytoremediation measures for soil detoxification.

(c)

Community-based trans-generational participatory health research to improve the understanding of chronic exposure to toxic metals; efforts must include mental and physical health, neurotoxicity and respiratory damage in children, cardiovascular and cognitive disorders in the elderly, and metabolic and respiratory damage in adults, related to chronic exposure to toxic metals and arsenic.

(d)

Promotion of community environmental monitoring together with local and regional governance models, integrating public participation.

Complementing the above, other authors suggest the need to reassess environmental definitions and criteria for mining tailing storage facilities and site selection, among other technical and regulatory changes involving governmental agencies, such as SERNAGEOMIN, the General Directorate of Waters (DGA), the Ministry of Health (MINSAL), and the Environmental Assessment Service (SEA), and to establish a regulatory framework for submarine deep-sea tailings disposal, considering the historical and recent mine tailing production in Chile, and the location of all large mining projects [17]. Along the same lines, it could be useful to consider ecological indicators and sustainability metrics for improving integrated surveillance systems [63].

5. Conclusions

The scientific evidence from 1978 to date demonstrates the negative impacts on the ecosystem and the human population exposed to toxic metals and arsenic. Geomorphological and biogeochemical alterations have been found on the Chañaral coast, affecting marine biodiversity and water quality. In humans, chronic exposure to toxic metals at low levels measured in street dust and urine raises health concerns in children and adults. In the social sciences, it is argued that the lack of environmental monitoring and data on human exposure contributes to an elevated health risk perception in the population.

In concordance with other authors, the improvement of the final disposal of mining tailings relies on the lessons learned from the past in many parts of the world. In fact, in Chañaral, as well as in other Chilean areas and globally, the improper management of mine tailings generates socio-environmental impacts on marine and terrestrial ecosystems that persist to this day. Considering the lack of information and practical experience on the effects of these practices, it is necessary to apply ethical approaches based on human rights and state-of-the-art available technologies, concerning society and ecosystems, to avoid repeating the mistakes of the past in present and future tailings management operations [17].

In conclusion, it is important to conceive the urban environment as a space where health must be prioritized and the lives of the inhabitants of Chañaral must be protected. Based on notions of social-environmental justice, it is considered fundamental to establish the minimum axes of analysis to seek solutions in public policies.