Uncontrolled sources are major contributors to air pollution and cancer risk in low and middle-income countries (LMICs).

An analytical method coupled to multivariate statistical analysis was developed based on transmission-mode direct analysis in real-time quadrupole time-of-flight mass spectrometry (TM-DART-QTOF-MS) to interrogate lipophilic compounds in seawater samples without the need for desalinization. An untargeted metabolomics approach is addressed here as seaomics and was successfully implemented to discriminate the sea surface microlayer (SML) from the underlying water (ULW) samples (n=22, 10 paired samples) collected during a field campaign at the Cabo Verde islands during September–October 2017. A panel of 11 ionic species detected in all samples allowed sample class discrimination by means of supervised multivariate statistical models. Tentative identification of the species enriched in the SML samples suggests that fatty alcohols, halogenated compounds, and oxygenated boron-containing organic compounds are available at the surface for air–water transfer processes. A subset of SML samples (n=5) were subjected to on-site experiments during the campaign by using a lab-to-field approach to test their secondary organic aerosol (SOA) formation potency. The results from these experiments and the analytical seaomics strategy provide a proof of a concept that can be used for an approach to identifying organic molecules involved in aerosol formation processes at the air–water interface.

Electronic nicotine delivery systems (ENDS) are battery-powered devices introduced to the market as safer alternatives to combustible cigarettes. Upon heating the electronic liquid (e-liquid), aerosols are released, including several toxicants, such as volatile organic compounds (VOCs). Benzene has been given great attention as a major component of the VOCs group as it increases cancer risk upon inhalation. In this study, several basic e-liquids were tested for benzene emissions. The Aerosol Lab Vaping Instrument was used to generate aerosols from ENDS composed of different e-liquid combinations: vegetable glycerin (VG), propylene glycol (PG), nicotine (nic), and benzoic acid (BA). The tested mixtures included PG, PG + nic + BA, VG, VG + nic + BA, 30/70 PG/VG, and 30/70 PG/VG + nic + BA. A carboxen polydimethylsiloxane fiber for a solid-phase microextraction was placed in a gas cell to trap benzene emitted from a Sub-Ohm Minibox C device. Benzene was adsorbed on the fiber during the puffing process and for an extra 15 min until it reached equilibrium, and then it was determined using gas chromatography-mass spectrometry. Benzene was quantified in VG but not in PG or the 30/70 PG/VG mixtures. However, benzene concentration increased in all tested mixtures upon the addition of nicotine benzoate salt. Interestingly, benzene was emitted at the highest concentration when BA was added to PG. However, lower concentrations were found in the 30/70 PG/VG and VG mixtures with BA. Both VG and BA are sources of benzene. Enhanced emissions, however, are mostly noticeable when BA is mixed with PG and not VG.

Per- and polyfluoroalkyl substances (PFAS) are persistent, emerging environmental contaminants with diverse chemical properties and widespread industrial and consumer uses. They are used as key components in products like surfactants, lubricants, fire-fighting foams, non-stick cookware, and water-repellent coatings. Additionally, their volatility and stability enable global transport, often reaching pristine environments across various regions. This review thoroughly examines the global literature on atmospheric PFAS, focusing on their distribution in polar, midlatitude, and tropical areas, the role and mechanisms of wet deposition in their atmospheric behavior, and their chemical transformation and phase partitioning in the atmosphere. While midlatitude industrial and consumer activities are primary sources, PFAS are transported globally. Moreover, wet deposition acts as a sink for atmospheric PFAS, with snow and sea spray especially effective at scavenging long-chain PFAS. Although secondary emissions through re-volatilization could occur, the main factors governing the fate of atmospheric PFAS are precursor transformations and phase partitioning. Volatile PFAS degrade in the atmosphere into more persistent and less volatile forms via oxidative and photochemical processes. The partitioning of PFAS between gas and particulate phases depends on functionalization and chain length, with some studies also emphasizing the role of meteorological conditions. Although this review covers a broad range of regions and environments, the existing literature remains limited, especially in areas such as the Antarctic Peninsula, the Middle East, Africa, and Latin America, where data gaps persist. Future research should focus on monitoring PFAS levels in these underrepresented regions and on enhancing the fundamental and mechanistic understanding of PFAS transformation pathways. Meanwhile, policymakers should prioritize implementing stricter emission controls, reforming regulations on legacy and precursor PFAS, and harmonizing PFAS regulations worldwide.

A transmission mode-direct analysis in real time-quadrupole time of flight-mass spectrometry (TM-DART-QTOF-MS)-based analytical method coupled to multivariate statistical analysis was developed to interrogate lipophilic compounds in seawater samples without the need of desalinization. An untargeted metabolomics approach addressed here as seaomics was successfully implemented to discriminate sea surface microlayer (SML) from underlying water (ULW) samples (n = 22, 10 paired samples) collected during a field campaign at the Cape Verde islands in September–October 2017. A panel of 11 ionic species detected in all samples allowed sample class discrimination by means of supervised multivariate statistical models. Tentative identification of these species suggest that saturated fatty acids, peptides, fatty alcohols, halogenated compounds, and oxygenated boron-containing organic compounds may be involved in water-air transfer processes and in photochemical reactions at the water-air interface of the ocean. A subset of SML samples (n = 5) were subject to on-site experiments during the campaign using a lab-to-the-field approach to test their secondary organic aerosol (SOA) formation potency. Results from these experiments and the analytical seaomics strategy provide a proof of concept that organic compounds play a key role in aerosol formation processes at the water/air interface.