Simona Galoppo

MP contamination in drinking water is an emerging public health concern, yet standardized analytical workflows and exposure assessments remain limited and fragmented. This study provides an exploratory assessment of MP exposure through drinking water, combining particle-resolved analysis with consumption-based estimates. Laser Direct Infrared (LDIR) spectroscopy was applied within the analytical workflow to characterize MPs across different drinking water supply types. Ten drinking-water samples (five bottled, two tap, two public dispensers, and one office dispenser) were analyzed within a 10–500 µm size window, and particle-resolved results were combined with a consumption survey to support preliminary exposure estimates. MPs in the 10–150 µm range were detected in six of ten samples, while tap waters and all blanks were particle-free, supporting analytical robustness. Bottled waters showed the highest MP abundances (6–148 particles L⁻¹) and mass concentrations (0.03–22.4 µg L⁻¹). Particle-size distributions were right-skewed and dominated by particles ≤ 30 µm. PET, PU, PA, and ABS predominated, consistent with packaging and dispensing origins. EDI estimates for bottled-water consumers ranged from 0.1008 to 0.3023 µg kg-bw⁻¹ day⁻¹ across three consumption scenarios (1–3 L day⁻¹). Despite the limited sample size, the results support LDIR for source discrimination and exposure screening, providing a basis for future research.

Environmental accumulation and human exposure to micro- and nanoplastics (MNPs) are increasing as plastic production rises, yet whether this has been paralleled by greater bioaccumulation in human lungs remains unclear. We conducted a comparative study of paraffin-embedded lung tissues collected post mortem from two series of autopsy cases from the same tertiary care medical center, including individuals who died in 1991 (n = 42) and in 2024 (n = 57). Microplastic abundance, size, and polymer type were assessed using laser-direct infrared (LDIR) imaging. Confirmatory analyses were performed in representative subsets using pyrolysis–gas chromatography/mass spectrometry and scanning electron microscopy. Collagen I staining and CD68 infiltration were evaluated to assess fibrosis and inflammation. MNPs were identified by LDIR in lung samples from 8 of 42 individuals (19%) who died in 1991 and 44 of 57 (77%) who died in 2024. The median MNP burden per gram of tissue (interquartile range) increased from 12.9 particles (11.3–13.7) to 19.9 (15.5–28.2), while mean particle diameter decreased. Polymer composition shifted from polyethylene predominance (51.7%) in 1991 to a more heterogeneous profile in 2024, including polyethylene terephthalate (28.4%), polyvinyl chloride (14.3%), and polystyrene (14.2%), findings corroborated by pyrolysis–gas chromatography/mass spectrometry and scanning electron microscopy. Lung samples containing MNPs showed greater CD68 and collagen I abundance than samples without detectable MNPs. Over the past three decades, MNP contamination of human lung tissue has become markedly more prevalent, compositionally diverse, and characterized by smaller particles, with accompanying histological features consistent with inflammation and fibrosis.

In the last few years, many industrial sectors have generated and discharged large volumes of saline wastewater into the environment. In the present work, the electrochemical removal of nitrogen compounds from synthetic saline wastewater was investigated through a lab-scale experimental reactor. Experiments were carried out to examine the impacts of the operational parameters, such as electrolyte composition and concentration, applied current intensity, and initial ammoniacal nitrogen concentration, on the total nitrogen removal efficiency. Using NaCl as an electrolyte, the N_TOT removal was higher than Na₂SO₄ and NaClO₄; however, increasing the initial NaCl concentration over 250 mg·L⁻¹ resulted in no benefits for the N_TOT removal efficiency. A rise in the current intensity from 0.05 A to 0.15 A resulted in an improvement in N_TOT removal. Nevertheless, a further increase to 0.25 A led to basically no enhancement of the efficiency. A lower initial ammoniacal nitrogen concentration resulted in higher removal efficiency. The highest N_TOT removal (about 75%) was achieved after 90 min of treatment operating with a NaCl concentration of 250 mg·L⁻¹ at an applied current intensity of 0.15 A and with an initial ammoniacal nitrogen concentration of 13 mg·L⁻¹. The nitrogen degradation mechanism proposed assumes a series–parallel reaction system, with a first step in which NH₄⁺ is in equilibrium with NH₃. Moreover, the nitrogen molar balance showed that the main product of nitrogen oxidation was N₂, but NO₃⁻ was also detected. Collectively, electrochemical treatment is a promising approach for the removal of nitrogen compounds from impacted saline wastewater.