Nickel (Ni)
Also known as: Ni2+
Overview
A transition metal and classified Group 1 human carcinogen (inhalation). Nickel is a potent contact allergen and immune sensitizer — it is one of the most common causes of allergic contact dermatitis worldwide. In the context of PBMC testing, nickel is particularly important because it directly activates Toll-like receptor 4 (TLR4) on monocytes and macrophages, mimicking bacterial endotoxin and driving chronic innate immune activation. Nickel compounds from implants, jewelry, and occupational exposure accumulate intracellularly in PBMCs.
Primary Sources
Stainless steel implants and surgical hardware, jewelry, coins, occupational exposure (electroplating, battery manufacturing, welding), dietary sources (whole grains, legumes, nuts, chocolate), cigarette smoke.
Health Effects
Allergic contact dermatitis, asthma, lung and nasal sinus cancer (Group 1 carcinogen), immune sensitization, TLR4-mediated chronic inflammation, ASIA syndrome from implants, cardiovascular toxicity.
Detection Method
This toxin is detected and quantified using HRMS + ICP-MS analysis of isolated PBMCs. The intracellular accumulation of this compound in lymphocytes and monocytes provides a more accurate reflection of chronic systemic burden than conventional serum or urine testing.