Cigarette smoking and nickel exposure

Abstract

The tobacco plant contains nickel and several other toxic metals, most probably absorbed from the soil, fertilizing products or from pesticides. It has been stated that nickel in a burning cigarette might form the volatile, gaseous compound, nickel tetracarbonyl, and thereby be introduced into the respiratory tract. Accordingly, the main objective of the present study was to find out if nickel content in inhaled smoke from ordinary cigarettes and nickel-contaminated cigarettes handmade by nickel process workers might be a supplementary source of nickel exposure to cigarette smoking process workers leading to additional risk of occupational respiratory cancer in these workers. Blood and urine samples from 318 randomly selected employees from Falconbridge Nickel Refinery in Kristiansand, Norway, allocated to 197 smokers and 121 non-smokers, were analysed for nickel content. Nickel quantities in tobacco from various cigarette brands, from nickel-contaminated cigarettes made by process workers or from cigarettes added known amounts of various nickel salts were analysed before being smoked. The cigarettes were smoked in a smoking machine device applying an electrostatic filter. Blood and urine, tobacco, ash and precipitates in the filter from the main stream smoke of the cigarettes were analysed for nickel quantities by atomic absorption spectrometry methods as previously described by the authors. The nickel concentrations in blood plasma and urine were quite similar among smokers and non-smokers, 6.2 and 48.1 microg L(-1) in smokers, and 6.4 and 50.5 microg L(-1) in non-smokers respectively. We recovered 1.1% or even less of nickel in the mainstream smoke after smoking the entire cigarettes without leaving any butt. Most of the tobacco nickel was recovered in the ash. We conclude that the inhaled nickel in the working atmosphere is probably the main source of the nickel exposure to the respiratory tract in these workers. It remains to be determined why cigarette smoking still seems to be a decisive cofactor in the development of respiratory tract cancer in nickel workers.

Scientific Opinion on the risks to public health related to the presence of nickel in food and drinking water

“…A mean Ni concentration of 0.03 μg/g was reported in smoke condensate collected from different US brands of cigarettes whereas most of the tobacco Ni was found to be present in the ash (Smith et al, 1997;Torjussen et al, 2003). On the assumption that a cigarette can contain Ni at an average 1-3 μg level, and that 10-20 % of Ni is released from the cigarette into the mainstream smoke, it was estimated that 2-12 μg of Ni could be inhaled for each pack of cigarettes smoked.…”

“…Notwithstanding the variability of the observations, up to approximately 10-20 % of the Ni content in cigarette tobacco may possibly be released in mainstream smoke in an unidentified chemical form (IARC, 1990;Torjussen et al, 2003;ATSDR, 2005). For instance, Chiba and Masironi (1992) reported that the average Ni levels in mainstream smoke were found to be 0.0726 and 0.0785 µg/cigarette at average Ni contents of respectively 0.64 and 1.15 µg/g tobacco (in general, there is 0.7-0.9 g tobacco per cigarette); however, in mainstream smoke quite higher Ni levels (up to 0.58 µg/cigarette) were also reported (Health Canada, 1994;Smith et al, 1997).…”

Evaluation of Essential Trace and Toxic Elements in Scalp Hair Samples of Smokers and Alcohol User Hypertensive Patients

“…As is the case with Cd, tobacco plants absorb Ni from the soil and concentrate it in the leaves [76]. Nickel has long been known to produce nasal and lung cancers [80].…”

“…The amount of Ni in tobacco plant lies between 0.640 and 1.15 mg/g, and varies greatly in cigarettes of different brands [80]. The possibility of trace and TEs contamination of various medications and its effects on the metabolism of TEs are still unknown.…”

Harmful Interactions of Non-Essential Heavy Metals with Cells of the Innate Immune System

“…Encasement in biofilm, a self-generated extracellular polymer matrix, is a survival strategy utilised by bacteria to promote persistence by evasion of both host defences and antibiotics, and has been implicated in 60-80% of all microbial infections [108]. Although the exact components of cigarette smoke which promote biofilm formation have not been established, it is noteworthy that nickel, which like Cd, Pb and V is also present in tobacco has been reported to promote biofilm formation by Escherichia coli in vitro [109,110]. Alternative sources of exposure to Cd, Pb and V include industrial and environmental pollution, high risk occupations and contaminated food such as fish [111,112].…”