Zoë Louise Fleming

Carbon dioxide (CO₂) emissions due to human activities are responsible for approximately 80% of the drivers of global warming, resulting in a 1.1 °C increase above pre-industrial temperatures. This study quantified the CO₂ assimilation and productivity of the brown macroalgae Lessonia spicata in the central Pacific coast of Chile, across seasonal and daily cycles, under different environmental stressors, such as temperature and solar irradiance. Measurements were performed using an infra-red gas analysis (IRGA) instrument which had a chamber allowing for precise quantification of CO₂ concentrations; additional photophysiological and biochemical responses were also measured. CO₂ assimilation, along with the productivity and biosynthesis of proteins and lipids, increased during the spring, coinciding with moderate temperatures (~14 °C) and high photosynthetically active radiation (PAR). Furthermore, the increased production of photoprotective and antioxidant compounds, including phenolic compounds, and carotenoids, along with the enhancement of non-photochemical quenching (NPQ), contribute to the effective photoacclimation strategies of L. spicata. Principal component analysis (PCA) revealed seasonal associations between productivity, reactive oxygen species (ROSs), and biochemical indicators, particularly during the spring and summer. These associations, further supported by Pearson correlation analyses, suggest a high but seasonally constrained photoacclimation capacity. In contrast, the reduced productivity and photoprotection observed in the summer suggest increased physiological vulnerability to heat and light stress. Overall, our findings position L. spicata as a promising nature-based solution for climate change mitigation.

Air pollution is one of the main problems facing humanity today. Megacities and large urban areas are pollution hotspots. Measuring pollutants and recording these measurements is key to developing effective strategies to reduce the pollution levels to which people are exposed. However, air quality monitoring presents significant challenges (e.g., investment costs, maintenance), which can lead to limited monitoring equipment. Despite this, Chile has an extensive air quality monitoring network, known as the National Air Quality Information System (SINCA in Spanish). This network has more than 200 monitoring stations that measure, record, and display information on pollution levels in different locations in Chile. In this study, all the information available from the SINCA network was systematized to evaluate the completeness of the records and the current trends of several pollutants in Chile. The main results show that most measurements focus on particulate matter and sulfur dioxide concentrations, and many of the measurement stations are located in the central part of the country (32° S–38° S). However, by splitting the data into five macrozones, one can see the regional air quality characteristics and changes. Furthermore, there are significant data gaps at some monitoring stations, which makes it difficult to elaborate a robust analysis. Regarding pollution levels, a significant decrease is observed for the peak Particulate Matter (PM_2.5) concentrations, with decreases of nearly 40% compared to concentrations at the beginning of the 2000s. This is consistent with the concentration trends, which show negative trends in most cases.

Awareness of air pollution and the associated environmental and health risks is growing worldwide. In order to answer the socio-environmental challenges posed by climate change, natural resource degradation and industrialization, scientists are advocating more holistic research linking environmental quality and public health. However, few studies have managed to integrate local communities’ concerns and knowledge with easy-to-use biomonitoring systems to produce science that contextualises their environment risk. This case study was carried out in an “environmental sacrifice zone” located in the Chacabuco province (Chile), where there have been no prior air quality studies or monitoring despite local populations suspecting metallic contamination. An interdisciplinary approach was proposed to create an innovative air quality assessment, combining both social and geographical data for risk perception and biomonitoring experiments with epiphyte plants (T. bergeri) in strategic sites. The cross-analysis of inhabitant interviews and cognitive maps shows that air pollution is perceived to be of greater risk in the northern and central part of the province. Microscopic and spectroscopic techniques highlight different origins of metal(loid)s in the air. Epiphyte plants reveal a site-dependent accumulation of pollutants (As, Cu, Cr, Mn, Pb, Ni, Zn). The collection of dust in Owen gauges and subsequent health risk assessment do not show evidence of hazard quotient or cancer risk. But enrichment factors and pollution indexes highlight that three sites can be classified as impacted, suggesting that more attention should be paid to chronic exposure and long-term environmental effects in this area. The social perception of air pollution appears to be correlated to the geochemical identification of some existing sources of metal(loid)s. Graphical abstract

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 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 (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.