Systematic review of the potential respiratory carcinogenicity of metallic nickel in humans

Abstract

The inhalation of dust containing certain nickel compounds has been associated with an increased risk of lung and nasal cancers in occupational studies of workers who process or refine sulfidic nickel ores and are exposed to relatively high levels of mixtures of water-soluble, sulfidic, oxidic, and/or metallic forms of nickel. We conducted a systematic review of the potential carcinogenicity of metallic nickel, focusing on cancers of the respiratory tract. We evaluated the quality and risk of bias (RoB) of the relevant epidemiology, experimental animal, and in vitro mechanistic studies using the National Toxicology Program's Office of Health Assessment and Translation (OHAT) RoB Rating Tool. We then used a systematic review protocol based on the OHAT approach to critically assess whether metallic nickel should be considered a human respiratory carcinogen. Our evaluation of the epidemiology studies indicates that there is no substantive evidence of increased respiratory cancer risk in workers exposed predominantly to metallic nickel. Animal evidence indicates that metallic nickel does not increase the incidence of respiratory tumors in rodents exposed by inhalation. The in vitro studies are limited in value, as they bypass normal clearance mechanisms. Nevertheless, the mechanistic evidence indicates that metallic nickel is not mutagenic but can induce DNA strand breaks under certain conditions. Based on a standard framework for assessing causality, we conclude that the evidence does not support a causal relationship between metallic nickel exposure and respiratory cancer in humans.

Effect of ouabain on calcium signaling in rodent brain: A systematic review of in vitro studies

“…Most quality features and measures of risk of bias (RoB) do not apply to or are not determined for biochemical studies of the kind here reviewed, and no standard quality assessment tool exists for in vitro studies. We based our study on quality/RoB criteria for in vitro studies presented by Prueitt et al ( Prueitt et al, 2020 ). Questions and criteria were modified to be relevant to the evaluation of studies of calcium homeostasis/signaling.…”

“…A study may have low RoB in some parameters, but high in others, which classifies it at an intermediate level, Tiers 2. Studies classified as Tier 3 have low quality and high RoB and those classified as Tier 1 have high quality and reliability ( Prueitt et al, 2020 ). The evaluation of the methodological quality of the studies included in this review was done by only one author.…”

A comprehensive review on the sources, essentiality and toxicological profile of nickel

“…36 In addition to its cancer-causing properties, nickel can also cause sensitization reactions in humans (Scheme 2). 6,17…”

“…Primarily Nickel is released into the atmosphere as aerosols as a result of human activities. 6,17 Approximately 1.4-1.8 times more emissions are generated by humans than by nature. During the 1980s, the combustion of fossil fuels accounted for 62% of anthropogenic emissions of atmospheric nickel.…”

“…For nickel particles injected intramuscularly, the order of carcinogenic activity towards rats has been determined as Ni 3 S 2 $b NiS (nickel(II) sulphide) > NiO (nickel(II) oxide) [ Ni 0 \ NiS (amorphous). 6,36,70,71 In the nickel rening industry the effluent byproducts like nickel sulphate, suldes, and oxides are carcinogenic when exposed to humans during nickel rening. A case study was conducted on the 100 sino-nasal cancer cases in nickel renery workers.…”