O. Orisakwe

Microplastics in bottled water and human health outcomes: a systematic review of multi-organ toxicity and mechanistic pathways.

This systematic review synthesized evidence on the health effects of microplastic exposure, with emphasis on organ-specific toxicity, molecular mechanisms, and implications for chronic disease. Following PRISMA 2020 guidelines, we searched PubMed, Scopus and Web of Science for peer-reviewed studies examining health outcomes associated with microplastic exposure relevant to bottled water consumption. Eligible studies included human observational studies, controlled animal experiments, and mechanistic in vitro investigations. Of 128 identified records, 15 studies met inclusion criteria: 3 human observational studies, 5 in vivo experiments, 4 in vitro investigations, and 3 mixed-design studies. Geographically, studies originated from China (40%), United States (20%), and other regions (40%). Polystyrene (10 studies), polyethylene, and polyethylene terephthalate (4 studies each) were most frequently investigated. Human biomonitoring confirmed microplastic presence in blood (3.15 ± 1.25 particles/mL), placental tissue (226-273 µg/g), and testicular samples (328 µg/g). Reproductive toxicity was the most consistently reported adverse outcome (5 studies), followed by hepatic, gastrointestinal, cardiovascular, renal, developmental, and neurological effects. Across studies, oxidative stress (reported in 12 studies), inflammatory activation (10 studies), endocrine disruption (4 studies), and mitochondrial dysfunction (4 studies) emerged as principal mechanistic pathways. Chronic exposure to microplastics from bottled water may contribute to multisystem toxicity through oxido-inflammatory mechanisms.

The toxic footprint of lead exposure: oxido-inflammatory biomarkers in urban populations of Niger Delta, Nigeria

Probabilistic eco-human health risk assessment of heavy metals in soils from Northwestern and Northcentral Nigeria using Monte Carlo simulation

Urban soil contamination by potentially toxic elements (PTEs) poses increasing ecological and public health concerns in rapidly industrializing environments. This study assessed PTE concentrations, contamination status, ecological risks, and human health implications of soils from Abuja and Kano, Nigeria, using deterministic and probabilistic risk assessment approaches. Sixteen topsoil samples (0–15 cm) collected from residential, commercial, and industrial locations were analyzed for Pb, Cd, Ni, Cr, and Al using atomic absorption spectrophotometry following aqua regia digestion. Mean concentrations of Pb (9.60 ± 4.29 vs 6.38 ± 3.08 mg/kg), Cd (1.53 ± 0.53 vs 1.12 ± 0.45 mg/kg), Ni (7.66 ± 1.71 vs 5.85 ± 1.42 mg/kg), Cr (9.86 ± 1.35 vs 8.23 ± 1.61 mg/kg), and Al (364.75 ± 96.47 vs 291.88 ± 80.39 mg/kg) were significantly higher in Kano than Abuja. Contamination assessment showed moderate Cd contamination (CF = 3.73–5.10), PLI values of 1.42 (Kano) and 1.16 (Abuja), Igeo values indicating unpolluted-to-moderately polluted soils, and enrichment factors suggesting moderate anthropogenic enrichment of Cd and Pb. Ecological risk indices revealed Cd as the dominant contributor, with Eᵣ values of 111.9–153.0 and total RI values of 176.4–229.8, indicating moderate-to-considerable ecological risk. Estimated daily intake followed the order ingestion > dermal > inhalation, with children exhibiting higher exposure levels than adults. Non-carcinogenic risks remained acceptable (HQ and HI < 1), with maximum HI values of 0.38 for children and 0.21 for adults in Kano. Incremental lifetime cancer risks values were highest for Cd (6.39 × 10⁻⁶ in Kano children and 4.38 × 10⁻⁶ in Kano adults) and lowest for Ni (4.41 × 10⁻⁹ in Kano children and 3.02 × 10⁻⁹ in Kano adults), with lower corresponding values in Abuja (9.78 × 10⁻⁷–1.71 × 10⁻1⁰ for children and 6.72 × 10⁻⁷–1.17 × 10⁻1⁰ for adults), all remaining within acceptable risk thresholds. Monte Carlo simulation confirmed consistently higher exposure probabilities in Kano. Continuous monitoring, stricter emission control, and targeted child-focused exposure mitigation are recommended for sustainable urban environmental management.

Human and environmental health risks of drugs in the environment

It is confirmed that pharmaceutical pollutants represent a multidimensional One Health challenge and primary recommendations include strengthening pharmaceutical waste management systems and medication take-back programs and implementing advanced wastewater treatment technologies.