Urban pollution typically arises from a combination of traffic emissions, dust resuspension, and domestic activities. In some cases, historical events leave toxic legacies that persist in urban environments for decades after emissions have ceased. In Arica, an industrial region in northern Chile, abandoned mining waste from the 1980s containing arsenic (As), lead (Pb), and zinc (Zn) has become integrated into the urban environment and remains a concern despite remediation efforts by local authorities. In this study, we analyzed 17 surface soil samples collected across Arica to quantify acid-extractable potentially toxic elements (PTEs) using EPA Method 3051 and atomic absorption spectroscopy. Elevated concentrations of As (up to 47 mg kg-1), Pb (up to 487 mg kg-1), and Zn (up to 1740 mg kg-1) were observed. Spatial analysis and screening-level risk assessment identified contamination hotspots consistent with both historical waste deposition and contemporary urban influences, indicating a complex exposure scenario for local communities. Unlike previous studies that focused on immediate post-remediation assessments, this study suggests that contamination persists and undergoes spatial reconfiguration more than three decades after the incident. These findings emphasize the need for sustained environmental governance addressing both historical and ongoing sources of urban soil contamination.
This study presents the first global data set of measured chlorinated paraffins (CPs), including short-chain (SCCPs), medium-chain (MCCPs), and long-chain chlorinated paraffins (LCCPs) in ambient air, derived from a single coordinated sampling network, i.e., the Global Atmospheric Passive Sampling (GAPS) network, using a passive sampling approach. Concentrations exhibited pronounced regional disparities, with the combined levels in two megacities-Lagos, Nigeria (512,000 pg/m(3)) and Beijing, China (258,000 pg/m(3)) exceeding by more than 1.5-fold the combined total levels observed across the rest of the world (similar to 459,000 pg/m(3)). Evidence of long-range atmospheric transport was observed at remote sites in western Canada (Little Fox Lake and Whistler), influenced by trans-Pacific air trajectories during the sampling period. These findings underscore the substantial global heterogeneity in the spatial distribution of CPs and the heavily disproportionate contributions of a few regions. Notably, the major producers/emitters, such as China, had several years of delay in ratifying the SCCP listing under the Stockholm Convention (Annex A, elimination since 2017 for congeners with > 48% chlorine content), and some countries have yet to ratify. Without the timely implementation of regulatory measures in these jurisdictions, global concentrations are expected to remain stagnant or even increase if emissions persist at current levels. These results further suggest that substantial time lags are likely before measurable declines in SCCP concentrations, and potentially in recently listed MCCPs, are observed even in regions where control measures are already in place. Hence, this global data set serves as a baseline for future assessments of temporal and spatial trends.
The global energy transition is accelerating the demand for copper and other energy-transition minerals worldwide, potentially expanding the existing large-scale mining across the Global South. Sustainability assessments of mining currently focus primarily on ambient outdoor concentrations of chemicals (metals) and commonly assume that buildings can buffer human exposure. Here we test this assumption in Calama, Chile, a desert city downwind of one of the world’s largest copper-mining complexes (Chuquicamata). We combined elemental, isotopic, and mineralogical analyses with oxidative potential measurements and zebrafish embryo assays to examine paired indoor and outdoor settled dust from 38 schools in Calama. Indoor concentrations of Cu, As, Pb, and Mo closely tracked outdoor levels and exceeded regional desert background by up to one order of magnitude, with minimal attenuation for As and Pb. Mineralogical and isotopic evidence indicated that the dust is not connected to fresh vehicles or combustion emissions, but rather to the mining industry. Additionally, the evidence showed enrichment in oxidized mining-derived particles, and indoor dust exhibited substantial oxidative potential. Zebrafish embryos exposed to dust extracts showed elevated heart rate under sublethal conditions. These results indicate that indoor environments in intensive mining landscapes, including classrooms, may be physically integrated into the surrounding extractive environment and should be incorporated into regular environmental monitoring, mine-closure planning, and just-transition governance.
Air quality management in Santiago (Chile) primarily relies on measuring atmospheric particulate matter and other criteria pollutants. This data is generated mostly by fixed-site outdoor monitoring stations, and the results are used to estimate population exposure. However, this approach may not be able to capture individual variability arising from differences in personal behaviors and microenvironmental transitions. Here we conducted an exploratory case study using residential outdoor polyurethane foam passive samplers and personal silicone wristbands to evaluate the potential polycyclic aromatic hydrocarbon exposure patterns among a limited number of residents of Santiago (Chile). Our results suggested that outdoor passive samplers and personal silicone wristbands revealed different but complementary PAH concentration patterns. Outdoor passive samplers captured regional spatial variability, whereas personal samplers revealed greater heterogeneity among individuals even when sharing the same residential environment. These findings support the value of integrating personal passive sampling into future assessment studies in urban environments of Chile.
Passive air monitoring requires polymer sorbents that combine selective interfacial interactions with fast capture of pollutants. We design porous polyurethane (PU) with tunable aromatic hard-segment (HS) content (MDI:BDO:PCL = 6:5:1, 4.5:5:1, 3:5:1, namely PU-1/PU-2/PU-3) and benchmark them against a commercial foam (C-PU). In these materials, HS domains act as physically cross-linked reinforcements embedded in a soft PCL matrix, or soft-segments (SS), so that the HS fraction/aromaticity governs microphase separation and crystallinity, tunes modulus, and elevates the dispersion component of the surface free energy (SFE). Multiscale characterization establishes a clear structure-property link. PU-2 provides the best balance of mechanical integrity, dispersive SFE = 46.33 +/- 0.21 mN m(-1), and a controlled pore architecture (similar to 150-300 mu m). In performance reference compound (PRC) calibrated deployments, PU-2 achieves 89.3 +/- 6.7% recovery, which is more than twice that of the commercial foam (41.2 +/- 6.6%). Field tests confirm superior uptake of low-molecular-weight polycyclic aromatic hydrocarbons, PAHs, (MW < 202 g mol(-1)), enabling urban-rural discrimination in 17 days (versus similar to 90 days for commercial foams). These results define a structure-property-performance pathway in which HS aromaticity governs microphase/thermal metrics and SFE, which together control selective uptake, thereby positioning hard-segment tuning as a practical polymer design lever for applied PU sorbents compatible with passive air monitoring requirements.
Assessing the impact of mining activity on the availability of environmental pollutants is crucial for informing health policies in anticipation of future production scenarios of critical minerals essential for the transition to a net-zero carbon society. However, temporal and spatial monitoring is often sparse, and measurements may not extend far enough back in time. In this study, we utilize variations of chemical elements contained in tree-rings collected in local villages from an area heavily affected by copper mining in the Atacama Desert since the early 20th century to evaluate the temporal distribution of pollutants and their relationship with local drivers. By combining time-varying data on local drivers, such as copper production and the dry tailings deposit area, we show how the surge in copper production during the 1990s, fueled by trade liberalization and increased international demand, led to a significant increment in the availability of metal(loid)s related to mining activities on indigenous lands. Our findings suggest that the environmental legislation in Chile may be underestimating the environmental impact of tailing dams in neighboring populations, affecting the well-being of Indigenous Peoples from the Atacama mining hotspot region. We argue that future changes in production rates driven by international demand could have negative repercussions on the environment and local communities. Therefore, mining emissions and the management of tailing dams should be carefully considered to anticipate their potential negative effects on human and ecosystem health.
The Atacama Desert's naturally elevated metal(loid)s pose a unique challenge for assessing the environmental impact of mining, particularly for indigenous communities residing in these areas. This study investigates how copper mining influences the dispersion of these elements in the wind-transportable fraction (<75 μm) of surface sediments across an 80 km radius. We employed a multi-pronged approach, utilizing spatial modeling to map element distributions, exponential decay analysis to quantify concentration decline with distance, regime shift modeling to identify dispersion pattern variations, and pollution assessment to evaluate impact. Our results reveal significant mining-driven increases in surface concentrations of copper (Cu), molybdenum (Mo), and arsenic (As). Notably, within the first 20 km, concentrations peaked at 1,016 mg kg⁻1 for Cu, 31 mg kg⁻1 for Mo, and a remarkable 165 mg kg⁻1 for As. Cu and Mo displayed significant dispersion, extending up to 50 km from the source. However, As exhibited the most extensive reach, traveling up to 70 km downwind, highlighting the far-reaching ecological footprint of mining operations. Mineralogical analyses corroborated these findings, identifying mining-related minerals in surface sediments far beyond the immediate mining area. Although pollution indices based on the proposed Local Geochemical Background reveal significant contamination across the study area, establishing accurate pre-industrial baseline values is essential for a more reliable assessment. This study challenges the concept of "natural pollution" by demonstrating that human activities exacerbate baseline metal(loid)s levels. Expanding monitoring protocols is imperative to comprehensively assess the combined effects of multiple emission sources, including mining and natural processes, in safeguarding environmental and human health for future generations.
Antarctica, once regarded as the last pristine desert untouched by human activity, is now facing increasing local impacts due to the rising presence of humans, primarily driven by scientific and touristic activities. This pilot study aimed to assess and compare the atmospheric concentrations of selected polycyclic aromatic hydrocarbons (PAHs) collected using passive air samplers and polyurethane foam disks as sorbent phases at different distances from a permanent (Capitán Arturo Prat) and a semi-permanent (Yelcho) research stations in the north-west region of the Antarctic Peninsula (WAP) during summer 2022 and throughout the year for the permanent station. The findings revealed that Antarctic research stations serve as potential primary sources of PAHs to the local atmosphere. Concentrations of PAHs decreased with increasing distance from suspected point sources, with significantly higher concentrations observed at Capitán Arturo Prat, possibly attributed to the presence of a waste incinerator. Moreover, concentrations in Capitán Arturo Prat during summer 2022 were up to six times higher compared to the rest of the year. Diagnostic ratios indicated that the detected PAHs were mainly derived from pyrogenic sources associated with biomass and wood burning, with the presence of retene suggesting potential non-reported wood burning sources.
The former Lepanto landfill in the Santiago Metropolitan Region in Central Chile ceased operations in 2002 after 24 years. Currently, a biogas recovery center operates on this site. The objective of this pilot study was to evaluate the atmospheric concentrations of two polycyclic aromatic hydrocarbons (PAHs, i.e., phenanthrene and fluoranthene) at three points downwind from the former Lepanto landfill using passive air samplers and polyurethane foam disks to provide 3-month average concentrations of contaminants during winter months. The results showed concentrations ranging between 2 and 65 ng m-3 and decreasing with distance from the former landfill. Given that the distance to other potential sources was similar in all sampling sites, the evidence found suggested that the former Lepanto landfill may contribute to the local PAH inventory. Thus, we suggest that former landfills are potential candidates for long-term monitoring as they can represent a less-known environmental liability for residents. Additionally, we provide insights on how the Chilean environmental protection system can establish reclamation steps for their management after closure. Graphical Abstract: In this manuscript, a pilot study is described for the evaluation of the atmospheric concentrations of phenanthrene and fluoranthene at three points near the former Lepanto landfill using passive air samplers to provide insights on how the Chilean environmental protection system can include these sites as potential candidates for long-term monitoring and establish reclamation steps for their management after closure. image
Non-targeted analysis (NTA) and suspect screening analysis (SSA) are powerful techniques that rely on high-resolution mass spectrometry (HRMS) and computational tools to detect and identify unknown or suspected chemicals in the exposome. Fully understanding the chemical exposome requires characterization of both environmental media and human specimens. As such, we conducted a review to examine the use of different NTA and SSA methods in various exposure media and human samples, including the results and chemicals detected. The literature review was conducted by searching literature databases, such as PubMed and Web of Science, for keywords, such as "non-targeted analysis", "suspect screening analysis" and the exposure media. Sources of human exposure to environmental chemicals discussed in this review include water, air, soil/sediment, dust, and food and consumer products. The use of NTA for exposure discovery in human biospecimen is also reviewed. The chemical space that has been captured using NTA varies by media analyzed and analytical platform. In each media the chemicals that were frequently detected using NTA were: per- and polyfluoroalkyl substances (PFAS) and pharmaceuticals in water, pesticides and polyaromatic hydrocarbons (PAHs) in soil and sediment, volatile and semi-volatile organic compounds in air, flame retardants in dust, plasticizers in consumer products, and plasticizers, pesticides, and halogenated compounds in human samples. Some studies reviewed herein used both liquid chromatography (LC) and gas chromatography (GC) HRMS to increase the detected chemical space (16%); however, the majority (51%) only used LC-HRMS and fewer used GC-HRMS (32%). Finally, we identify knowledge and technology gaps that must be overcome to fully assess potential chemical exposures using NTA. Understanding the chemical space is essential to identifying and prioritizing gaps in our understanding of exposure sources and prior exposures. IMPACT STATEMENT: This review examines the results and chemicals detected by analyzing exposure media and human samples using high-resolution mass spectrometry based non-targeted analysis (NTA) and suspect screening analysis (SSA).
Oxidative potential (OP) has gained attention as a parameter that can reveal the ability of different properties of particulate matter (PM) to generate reactive oxygen species (ROS) as one single value. Moreover, OP is also believed to be a predictor of toxicity and hence the health effects of PM. This study evaluated the OP of PM10, PM2.5,and PM1.0samples using dithiothreitol assays in two cities of Chile (Santiago and Chillán). The results showed that the OP was different between cities, PM size fractions, and seasons. Additionally, OP was strongly correlated with certain metals and meteorological variables. Higher mass-normalized OP was observed during cold periods in Chillán and warm periods in Santiago and was associated with PM2.5 and PM1. On the other hand, volume-normalized OP was higher during winter in both cities and for PM10. Additionally, we compared the OP values to the Air Quality Index (AQI) scale and found cases of days that were classified as having "good" air quality (supposed to be less harmful to health) showing extremely high OP values that were similar to those on days that were classified as "unhealthy". Based on these results,we suggest using the OP as a complementary measure to the PM mass concentration because it includes important new information related to PM properties and compositions that could help improvecurrent air quality management tools.
Bottled water has emerged as a possible healthier alternative due to concerns about the quality of drinking water sources. However, recent studies have detected worrying concentrations of environmental contaminants in bottled water, including microplastics. Therefore, it is an emerging need to quantify their concentrations in local suppliers which could differ among countries and regions. In this work, we used fluorescence microscopy with Nile Red for the identification and quantification of potential microplastics in twelve brands of bottled water distributed in the Santiago Metropolitan Region of Chile. The average concentration of microplastics was 391 & PLUSMN; 125 p L-1, while the highest concentration observed was 633 & PLUSMN; 33 p L-1. Microplastics between 5 and 20 & mu;m were the major contributors, a size fraction that has been reported to be susceptible to accumulate in the digestive tract or generate potential alterations in the lymphatic and circulatory systems. The estimated daily intake value for per capita was estimated to be 229 p kg-1 year- 1 for people weighing 65 kg and 198 p kg-1 year- 1 for those weighing 75 kg.
Indigenous communities from northern Chile have historically been exposed to the impacts of massive copper industrial activities conducted in the region. Some of the communities belonging to the Alto El Loa Indigenous Development Area are located less than 10 km from the "Talabre" tailings dam, which contains residues from copper production and other metals that can be toxic to human health (e.g., As, Sb, Cd, Mo, Pb). Given the increasing demand of copper production to achieve net-zero emission scenarios and concomitant expansions of the tailings, the exposure to toxic metals is a latent risk to local communities. Despite the impact that copper production could generate on ancestral communities from northern Chile, studies and monitoring are limited and the results are often not made accessible for local communities. Here, we evaluate such risks by characterizing metal concentrations in dust collected from roofs and windows of houses from the Alto El Loa area. Our results showed that As, Sb, Cd, Cu, Mo, Ag, S, and Pb concentrations in these matrices can be connected to local copper mining activities. Additionally, air transport models indicate that high concentrations of toxic elements (As, Sb, and Cd) can be explained by the atmospheric transport of particles from the tailings in a NE direction up to 50 km away. Pollution indices and Health Risk Assessment suggested a highly contaminated region with a health risk for its inhabitants. Our analysis on a local scale seeks to make visible the case of northern Chile as a critical territory where actions should be taken to mitigate the effects of mining in the face of this new scenario of in-ternational demand for the raw materials necessary for the transition to a net-zero carbon global society.
Agriculture is one of the main economic activities in Chile and is associated with extensive use of pesticides, which can represent a risk to the environment and to human health. Currently, there are over 400 pesticides approved for commerce in Chile, including chemicals banned in other countries (e.g., flocoumafen and chlorfenapyr). An empirical analysis of their potential environmental effects is difficult due to this large number, thus opening the doors for the use of computational tools for prioritization efforts based on their persistence, bioaccumulation, and transport potential in the environment. The main objectives of this study were to estimate the properties and environmental distribution of pesticides approved for commerce in Chile and to generate a priority list for further evaluation in local environments. We used the Estimation Program Interface Suite interface to estimate the distribution coefficients, half-lives, and bioaccumulation potential of all pesticides registered in the Chilean Agriculture and Livestock Services. Additionally, the Pov & LRTP Screening Tool was used to estimate their overall persistence and long-range transport potential in the environment. The results were used to develop a P-B-lon range transport (LRT) score, which considered persistence, bioaccumulation, and long-range transport potential. All pesticides were compared to a group of polychlorinated biphenyls (PCBs), used as reference compounds, to generate a list of priority pesticides with persistent organic pollutants characteristics. The results showed that most pesticides were distributed between the organic phase and water, where they also showed the longest half-lives and bioaccumulation potential. A group of 21 pesticides showed relatively high P-B-LRT scores, compared to PCBs, and were classified as priority compounds. The list was further refined based on the volume of sales for each pesticide. Integr Environ Assess Manag 2023;19:676-683. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
The implementation of confinement and physical distancing measures to restrict people?s activities and transit in the midst of the COVID-19 pandemic allowed us to study how these measures affect the air quality in urban areas with high pollution rates, such as Santiago, Chile. A comparative study between the concentrations of PM10, PM2.5, NOx, CO, and O3 during the months of March to May 2020 and the corresponding concentrations during the same period in 2017?2019 is presented. A combination of surface measurements from the air quality monitoring network of the city, remote satellite measurements, and simulations of traffic activity and road transport emissions allowed us to quantify the change in the average concentrations of each pollutant. Average relative changes of traffic emissions (between 61% and 68%) implied statistically significant concentrations reductions of 54%, 13%, and 11% for NOx, CO, and PM2.5, respectively, during the pandemic period compared to historical period. In contrast, the average concentration of O3 increased by 63% during 2020 compared to 2017?2019. The nonlinear response observed in the pollution levels can be attributed to the changes in the vehicular emission patterns during the pandemic and to the role of other sources such as residential emissions or secondary PM.
A monitoring campaign of the atmospheric particulate matter (PM) size distribution (between 0.25 and 10 mu m in diameter (Dp)) in an urban area with high levels of air pollution between June 2018 and May, 2019 is presented. The relative contribution of 24 size fractions to the total number and mass concentration of PM was analyzed using an aerosol spectrometer. Local meteorological parameters and their effect on the PM concentrations were also evaluated. The size-fractionated particle mass concentrations showed the accumulation (Dp < 1 mu m) and coarse (1 mu m < Dp < 10 mu m) modes. The highest contribution of the accumulation mode was observed during autumn and winter (reaching 99.7 % and 35.2 % of the total number and mass concentrations, respectively). High relative humidity and low temperatures were strongly correlated with high concentrations for the smaller PM fractions, which can be connected to the increase of residential emissions of PM derived from wood burning sources in winter months. The larger PM fractions showed higher concentrations during the spring and summer months, potentially because of dust resuspension due to the high vehicular traffic in the vicinity. High PM concentrations of the larger fractions were favored by the lack of precipitation events and stronger winds during this time of the year. The results showed the importance of the PM1 fraction to improve the source apportionment studies in urban areas and provide information about the potential health effects associated to high PM concentration events.
ABSTRACT We present the effects of the confinement and physical distancing policies applied during the COVID-19 pandemic on the concentrations of PM10, PM2.5, NO, NO2 and O3 in 16 cities in central and southern Chile. The period between March and May in 2020 was compared with the corresponding months during 2017-2019, using surface data and satellite information. The relative percent changes in the concentration of atmospheric pollutants, and the meteorological variables observed between these two periods were used to quantify the effects of the lockdowns on the local air quality of the urban areas studied. The results showed statistically significant changes in 11 of the 16 cities. Significant relative changes between +14% and -33% were observed for PM10 in 9 cities; while statistically significant changes between -6% and -48% were evident for PM2.5 in 10 cities. Significant decreases between -27% and -55%, were observed in 4 cities in which NO2 data were available; while significant increases in O3, between 18% and 43%, were found in 4 of the 5 cities with available data. The local meteorological variables did not show significant changes between both periods. In all the cities studied, one of the main PM sources is wood burning for residential heating. Although the quarantine imposed during the health emergency could have induced an increase in residential emissions, these were compensated with the reductions in vehicular and/or industrial emissions. Therefore, these results should be carefully interpreted and should inspire new research considering the social, cultural, and economic factors that could alter the common emission patterns and air quality of urban centers.
Non-targeted analysis (NTA) workflows using mass spectrometry are gaining popularity in many disciplines, but universally accepted reporting standards are nonexistent. Current guidance addresses limited elements of NTA reporting-most notably, identification confidence-and is insufficient to ensure scientific transparency and reproducibility given the complexity of these methods. This lack of reporting standards hinders researchers' development of thorough study protocols and reviewers' ability to efficiently assess grant and manuscript submissions. To overcome these challenges, we developed the NTA Study Reporting Tool (SRT), an easy-to-use, interdisciplinary framework for comprehensive NTA methods and results reporting. Eleven NTA practitioners reviewed eight published articles covering environmental, food, and health-based exposomic applications with the SRT. Overall, our analysis demonstrated that the SRT provides a valid structure to guide study design and manuscript writing, as well as to evaluate NTA reporting quality. Scores self-assigned by authors fell within the range of peer-reviewer scores, indicating that SRT use for self-evaluation will strengthen reporting practices. The results also highlighted NTA reporting areas that need immediate improvement, such as analytical sequence and quality assurance/quality control information. Although scores intentionally do not correspond to data/results quality, widespread implementation of the SRT could improve study design and standardize reporting practices, ultimately leading to broader use and acceptance of NTA data.