Absorption and excretion of cobalt in the hard metal industry

doi:10.1016/0048-9697(94)90141-4

Science of The Total Environment

Volume 150, Issues 1–3, 30 June 1994, Pages 141-144

https://doi.org/10.1016/0048-9697(94)90141-4 Get rights and content

Abstract

Absorption and excretion of cobalt in the hard metal industry was investigated by means of ambient air and urine measurements in three factories with high levels of environmental cobalt pollution. In the presence of poor hygiene conditions and permission to smoking during work, there was no relationship between cobalt ambient air and cobalt urine concentrations. Such a finding was therefore attributed to a substantial skin contact. A simple experiment of skin exposure to freshly mixed or waste powder on volunteers identified a ten-fold increase of cobalt in urine in the post-exposure samples, thus confirming the contribution of dermal exposure as a route of entry. An improvement in the hygiene of the working conditions helped to investigate the relationship between exposure and excretion level. Cobalt uptake through the different routes of entry may be substantial, and requires a more prolonged exposure-free period so that the excretion rate can be reduced to the reference population level.

References (8)

ACGIH (American Conference of Governmental Industrial Hygienists)
1991–1992 Threshold Limit Values and Biological Exposure Indices
B.L. Carson et al.
Toxicology and Biological Monitoring of Metals in Humans
A.G. Davison et al.
Interstitial lung disease and asthma in hard-metal workers: bronchoalveolar lavage, ultrastructural, and analytical findings and results of bronchial provocation tests
Thorax
(1983)
ILO (International Labour Office)
Occupational Exposure Limits for Airborne Toxic Substances

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Cited by (51)

Cobalt
2021, Handbook on the Toxicology of Metals: Fifth Edition
Cobalt is a relatively rare element of the Earth's crust, essential to mammals in the form of cobalamin (vitamin B12). In humans, the dietary intake of cobalt varies between 5 and 50 μg/day, most of it in the inorganic form. Vitamin B12 represents only a small fraction of the oral Co intake. The oral bioavailability of inorganic cobalt compounds varies between 5% and 45% according to their respective water solubility. In occupational settings, workers can be exposed by inhalation to mainly inorganic cobalt compounds. The absorption rate of inhaled cobalt also varies with the species under consideration. Cobalt does not accumulate in the organism and is rapidly excreted, mainly in the urine. The concentration of cobalt in urine or in blood can be used as a biomarker of recent exposure to soluble cobalt species. Co²⁺ ions are genotoxic, and several forms of cobalt are carcinogenic in experimental animals. Upon inhalation exposure, the respiratory system is the main target organ of cobalt in humans (asthma, fibrosing alveolitis). The risk of fibrosing alveolitis (hard metal disease) and lung cancer is specific of the hard metal industry, where workers are exposed to cobalt metal mixed with tungsten carbide particles. Other target organs include the erythropoietic system, the myocardium, the thyroid gland, and the nervous system. In patients with cobalt alloy implants, especially metal-on-metal hip prostheses, endogenous exposure to cobalt can result in local and/or systemic toxicity. The reproductive toxicity of cobalt compounds is not well documented.
A novel approach to monitor skin permeation of metals in vitro
2020, Regulatory Toxicology and Pharmacology
Citation Excerpt :
This is cause for concern when risk assessments must rely on potentially misleading default assumptions about skin absorption, which are generally set to 0%, 10% or 100% (USEPA, 2003, USEPA, 2007; ECHA, 2012, ECHA, 2016). However, some data on the contribution from skin exposure to systemic metal absorption are available from occupational studies where both skin- and urine/blood levels have been measured (Scansetti et al., 1994; Sun et al., 2002; Klasson et al., 2017; Kettelarij et al., 2018; Linde et al., 2018). There are also studies that specifically investigated permeation of metals into and through skin.
How metals permeate skin is poorly understood. Risk assessments tend to take default approaches to account for the dermal route, often using numbers of questionable relevance. Moreover, simultaneous exposure to multiple metals may affect the permeation of individual metals. To investigate this, we developed an experimental setup where receptor medium circulates directly from a conventional diffusion cell for in vitro skin absorption into an inductively coupled plasma mass spectrometer (ICP-MS), enabling continuous measurement of metal concentration. Full-thickness piglet skin was used as diffusion barrier, artificial sweat as donor medium and phosphate buffered saline as receptor medium. Percutaneous absorption from donor medium containing 2 mmol/L of nickel, cobalt, or chromium or all three combined was monitored for 2 h. Metals retained in skin were quantified post-exposure. Percutaneous absorption of nickel was faster in single than in combined exposure; for cobalt and chromium no such difference was apparent. Similar amounts of the three metals were retained in skin after single exposure, and retention was consistently higher for each metal after combined exposure. This study provides proof-of-concept for a method that reliably detects concentration changes in physiologically relevant medium. It may shed light on skin absorption and permeation kinetics of metals and risks associated with metal exposure.
Cobalt toxicity in humans—A review of the potential sources and systemic health effects
2017, Toxicology
Citation Excerpt :
The combination of Co with WC is assumed to enhance the cellular uptake of Co and modulate its biological reactivity and toxic effect (Barceloux, 1999; Lison and Lauwerys, 1992; Broding et al., 2009). Bodily cobalt uptake in the hard metal industry mainly results from inhalation of hard metal dust, although dermal uptake has also been demonstrated (Scansetti et al., 1994). When only considering the inhalation pathway, the uptake is determined by the airborne workplace concentration, the duration of the working shift, the breathing volume per minute, and the percent retention of dust in the airways.
Cobalt (Co) and its compounds are widely distributed in nature and are part of numerous anthropogenic activities. Although cobalt has a biologically necessary role as metal constituent of vitamin B₁₂, excessive exposure has been shown to induce various adverse health effects. This review provides an extended overview of the possible Co sources and related intake routes, the detection and quantification methods for Co intake and the interpretation thereof, and the reported health effects. The Co sources were allocated to four exposure settings: occupational, environmental, dietary and medical exposure. Oral intake of Co supplements and internal exposure through metal-on-metal (MoM) hip implants deliver the highest systemic Co concentrations. The systemic health effects are characterized by a complex clinical syndrome, mainly including neurological (e.g. hearing and visual impairment), cardiovascular and endocrine deficits. Recently, a biokinetic model has been proposed to characterize the dose-response relationship and effects of chronic exposure. According to the model, health effects are unlikely to occur at blood Co concentrations under 300 μg/l (100 μg/l respecting a safety factor of 3) in healthy individuals, hematological and endocrine dysfunctions are the primary health endpoints, and chronic exposure to acceptable doses is not expected to pose considerable health hazards. However, toxic reactions at lower doses have been described in several cases of malfunctioning MoM hip implants, which may be explained by certain underlying pathologies that increase the individual susceptibility for Co-induced systemic toxicity. This may be associated with a decrease in Co bound to serum proteins and an increase in free ionic Co²⁺. As the latter is believed to be the primary toxic form, monitoring of the free fraction of Co²⁺ might be advisable for future risk assessment. Furthermore, future research should focus on longitudinal studies in the clinical setting of MoM hip implant patients to further elucidate the dose-response discrepancies.
Cobalt
2015, Handbook on the Toxicology of Metals: Fourth Edition
Cobalt is a relatively rare element of the Earth’s crust, essential to mammals in the form of cobalamin (vitamin B₁₂). In humans, dietary intake of cobalt varies between 5 and 50 μg/day and most of it is inorganic with vitamin B₁₂ representing only a small fraction. The oral bioavailability of inorganic cobalt compounds is a function of their water solubility and varies from 5 to 45%. In occupational settings, workers are exposed to mainly inorganic cobalt compounds by inhalation of dust. The absorption rate of inhaled cobalt also varies with the species under consideration. Cobalt does not accumulate in the organism and is rapidly excreted, mainly in urine. The concentration of cobalt in urine or in blood can be used as a biomarker of recent exposure to soluble cobalt species. Cobalt(II) ions are genotoxic and several forms of cobalt are carcinogenic in experimental animals. Upon inhalation exposure, the respiratory system is the main target organ of cobalt in humans (asthma, fibrosing alveolitis, lung cancer), with a higher risk of fibrosing alveolitis (hard metal disease) and lung cancer in the hard metal industry, where workers are exposed to cobalt metal mixed with tungsten carbide particles. Other target organs include the hematopoietic system, the myocardium, the thyroid gland, and the nervous system. Endogenous exposure to cobalt, sometimes associated with local and/or systemic toxicity, can occur in patients with cobalt alloy implants, especially metal-on-metal hip prostheses. The reproductive toxicity of cobalt compounds is not well documented.
Safety evaluation of metal exposure from commonly used moisturizing and skin-lightening creams in Nigeria
2015, Regulatory Toxicology and Pharmacology
Citation Excerpt :
Cobalt powders can more easily permeate damaged skin than intact skin (Larese Filon et al., 2009). It has been shown that cutaneous exposure to Co has led to higher concentrations of urinary Co in volunteers (Scansetti et al., 1994). However, animal studies have shown that the slow elimination of Co through the urinary system following dermal exposure to Co salts, and the prolonged skin retention of Co, formed the basis for consequential immune responses in dermal tissue (Lacy et al., 1996).
The concentrations of ten metals (Cd, Pb, Ni, Cr, Cu, Co, Fe, Mn, Zn and Al) were measured in some commonly used moisturizing and skin-lightening creams in Nigeria with a view to providing information on the risk of exposure to metals from the use of these products. The metal concentrations in these products were measured by atomic absorption spectrometry after acid digestion of the samples. The measured concentrations of metals in the skin moisturizing creams ranged from <0.15 to 6.3 μg/g Cd, <0.02 to 17.5 μg/g Cu, 2.25 to 6.25 μg/g Cr, <0.25 to 124.3 μg/g Al, 0.2 to 7.3 μg/g Pb, <0.03 to 10.7 μg/g Ni, 17.3 to 372.0 μg/g Zn, <0.02 to 1.0 μg/g Co, 17.75 to 28.8 μg/g Mn, <0.1 to 89.8 μg/g Fe while the concentrations of metals in the skin-lightening products ranged from <0.15 to 16.5 μg/g Cd, <0.02 to 10.0 μg/g Cu, 4.25 to 8.0 μg/g Cr, <0.25 to 128.0 μg/g Al, 0.5 to 4.5 μg/g Pb, <0.03 to 1.65 μg/g Ni, 24.7 to 267.5 μg/g Zn, <0.02 to 2.5 μg/g for Co, 19.3 to 31.8 μg/g Mn, 9.5 to 211.63 μg/g Fe. In a significant number (>93%) of the samples investigated the concentrations of Pb, Cd, Ni and Co were below the specified limit, or the maximal limit for impurities in colour additives in cosmetics for external use. However, Cr was found at concentrations above the allergenic limit of 1 μg/g. The results also showed that skin-lightening creams contained higher concentrations of the studied metals than the moisturizing creams, except for Ni, which indicates that persons who uses skin-lightening creams in preference to moisturizing ones, are exposed to higher concentrations of metals.
Toxic metals contained in cosmetics: A status report
2014, Regulatory Toxicology and Pharmacology
Citation Excerpt :
Moreover, Co powders appeared to penetrate the damaged skin more easily than intact skin (Larese Filon et al., 2009). It has been shown that volunteers who were cutaneously exposed to Co had higher concentrations of urinary Co (Scansetti et al., 1994). A study on animals revealed that the slow elimination of Co in urine following dermal application of Co salts and the prolonged skin retention of Co posed the basis for consequential immune responses in the dermal tissue (Lacy et al., 1996).
The persistence of metals in the environment and their natural occurrence in rocks, soil and water cause them to be present in the manufacture of pigments and other raw materials used in the cosmetic industry. Thus, people can be exposed to metals as trace contaminants in cosmetic products they daily use. Cosmetics may have multiple forms, uses and exposure scenarios, and metals contained in them can cause skin local problems but also systemic effects after their absorption via the skin or ingestion. Even this, cosmetics companies are not obliged to report on this kind of impurities and so consumers have no way of knowing about their own risk. This paper reviewed both the concentration of metals in different types of cosmetics manufactured and sold worldwide and the data on metals’ dermal penetration and systemic toxicology. The eight metals of concern for this review were antimony (Sb), arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), mercury (Hg), nickel (Ni) and lead (Pb). This was because they are banned as intentional ingredients in cosmetics, have draft limits as potential impurities in cosmetics and are known as toxic.

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Absorption and excretion of cobalt in the hard metal industry

Abstract

1991–1992 Threshold Limit Values and Biological Exposure Indices

Toxicology and Biological Monitoring of Metals in Humans

Interstitial lung disease and asthma in hard-metal workers: bronchoalveolar lavage, ultrastructural, and analytical findings and results of bronchial provocation tests

Thorax

Occupational Exposure Limits for Airborne Toxic Substances