Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. 
Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was reviewed?
This paper is a comprehensive review of Nickel human health toxicity, synthesizing evidence on nickel’s chemistry, exposure routes, molecular mechanisms of toxicity (oxidative stress, mitochondrial dysfunction, and epigenetic modulation), clinical outcomes (allergy, respiratory disease, cancer, reproductive and teratogenic effects), and remediation strategies including phytoremediation and biosorption. The review draws on epidemiology, in vivo and in vitro toxicology, mechanistic molecular studies, and remediation literature to map how nickel exposure translates into health risk and environmental persistence.
Who was reviewed?
The authors reviewed human epidemiological cohorts (notably occupational cohorts in nickel refining and metal-working), in vivo animal studies (rats, hamsters, mice), in vitro human and animal cell models (lung epithelial cells, hepatoma, Leydig and germ cells, immune cells), and environmental/plant studies on hyperaccumulators and microbes used for remediation. The materials examined include soluble and insoluble nickel salts, nickel nanoparticles, and nickel alloys, reflecting real-world industrial and consumer exposure relevant to regulators and certification programs.
Most Important Findings
| Key findings | Relevance to HTMC program |
|---|---|
| Nickel exposure is widespread: air (emissions, combustion), water/food (leaching, processing, high-Ni foods), dermal (jewelry, coins), inhalation (fumes, welding, nanoparticles). | HTMC must test air, water, food-contact surfaces, and consumer items; account for solubility and particle size (nano vs. bulk). |
| Toxic outcomes include allergy, respiratory disease, lung/nasal cancer (IARC Group 1), cardiovascular and kidney damage, reproductive toxicity, teratogenicity, and neurotoxicity. | Stricter limits for inhalable/insoluble nickel; mandate allergy risk testing and consumer product labeling. |
| Require nanoparticle size/surface characterization, release testing under use conditions, and nano-specific toxicology endpoints. | Include ROS and mitochondrial assays in HTMC bioaccessibility and hazard ranking protocols. |
| Epigenetic/genotoxic effects: nickel displaces Fe²⁺ in enzymes, alters histones, induces DNA hypermethylation, condenses chromatin, silences genes—linked to carcinogenesis. | Recognize epigenetic carcinogenesis; integrate biomarkers or long-term bioassays for certification. |
| Nanoparticles and nanowires show enhanced ROS, cytotoxicity, and reproductive toxicity; welding and high-temp processes generate Ni nanoparticles. | Remediation includes phytoremediation (Alyssum spp., Rinorea) and microbial biosorption; effectiveness varies by soil, Ni concentration, and cost. |
| Remediation includes phytoremediation (Alyssum spp., Rinorea) and microbial biosorption; effectiveness varies by soil, Ni concentration, cost. | Relevance to the HTMC program |
Key implications
For a heavy metal certification program, key actions include: (1) form-specific assessment of soluble, insoluble, and nano nickel due to differing hazards; (2) occupational controls and monitoring with particle-size characterization and air sampling, reflecting lung-cancer risk; (3) consumer-item migration testing (e.g., EN1811-style) to limit allergy risk; (4) inclusion of sub-genotoxic markers such as epigenetic endpoints and enzyme-inhibition assays for long-term carcinogenic evaluation; and (5) remediation certification recognizing validated site-specific approaches like phytoremediation, with documented plant selection, harvest, and metal recovery or disposal.
Citation
Genchi G, Carocci A, Lauria G, Sinicropi MS, Catalano A. Nickel: Human Health and Environmental Toxicology. Int J Environ Res Public Health. 2020;17(3):679. doi:10.3390/ijerph17030679
Nickel is a widely used transition metal found in alloys, batteries, and consumer products that also contaminates food and water. High exposure is linked to allergic contact dermatitis, organ toxicity, and developmental effects, with children often exceeding EFSA’s tolerable daily intake of 3 μg/kg bw. Emerging evidence shows nickel crosses the placenta, elevating risks of preterm birth and congenital heart defects, underscoring HMTC’s stricter limits to safeguard vulnerable populations.
