HEAVY METAL
(Cd, Cu, Pb, Cr, Zn, Hg) CONCENTRATIONS IN TOBACCO OF COMMONLY SMOKED CIGARETTE
BRANDS PURCHASED IN GERMANY, CHINA, RUSSIA, INDIA AND CANADA
German Müller, D. Eggersgluess and N. Najardhanu Raju* Institute of Environmental Geochemistry Heidelberg University, INF 236, D-69120 Heidelberg, Germany
E-mail gmueller@ugc.uni-heidelberg.de
*permanent address Dept. Geology, Sri Venkateswara
Univ., Tirupati 517 502, India
Abstract
Heavy metal (Cd, Cu, Pb, Cr,
Zn, Hg) concentrations of tobacco from altogether 46 brands
of cigarettes commonly smoked
in Germany, China, Russia, India and Canada were analysed with flame- and
flameless AAS and cold vapour AAS.
Zn contents show the least
variations within the five countries. The same holds true for Cu with the
exception of Canada with significantly low concentrations.
Highest Cd contents were
detected in Chinese brands with about five times higher concentrations than in
Indian cigarettes.
For Pb again China is the
winner with concentrations at least 3 times higher than in all other
countries.
Cr contents are highest in
Germany and lowest in Indian brands, Hg contents are lowest in Russia and
Canada.
Hg contents are slightly
higher in Indian tobaccoes and show the largest SD.
Cd contents in German
cigarettes remained constant if compared with 1994 values.
Introduction
Our previous studies on heavy
metals in tobacco of cigarettes commonly smoked in Germany concentrated on
variations of cadmium contents with time between 1969 (Szadkowski et al. 1969),
1978, 1985 and 1994 (Müller 1979, 1985,1995). It could be shown, that the mean
contents of this metal, which had been declared as carcinogenic to humans
from the International Agency for the Research on Cancer (IARC, 1993) of the
World Health Organization (WHO) showed a decreasing tendency during these
intervals from 1.41 to 1.38 to 1.30 to 1.04 µg/g tobacco.
Our present study intents to
continue the time series for cadmium in tobacco of cigarettes commonly smoked
in Germany, but also contains analytical data on other relevant heavy metals
not only for cigarettes smoked in Germany but also for tobacco of cigarettes of
some other countries representing different stages of economic development,
size of population and smoking habits.
In some respect our paper
could be an (incomplete) continuation of an already classical paper by
Elinder et al. (1983): Cadmium exposure from cigarettes: variations with time
and country where purchased. Their statement no systematic change in the
cadmium concentration of cigarettes with time could be revealed, however,
holds no longer true for the tobacco of cigarettes smoked in Germany.
Materials and analytical
methods
From 9 - 10 cigarette brands
randomly purchased between April and July 1998 in five different countries 10
cigarettes were selected from their pack. After removing filter and paper the
tobacco was freeze dried and homogenized. 1 g tobacco was transferred into 50
ml Erlenmayer beakers, moistened with aqua dest., and - after addition of 10 ml
nitric acid- heated at 50°C for 30 minutess, followed by heating at
150°C on a sandbath for 2 hours.
The heavy metals Cd, Pb, Cu,
Zn, Cr were analyzed by flame and flameless atomic absorption spectroscopy, Hg
by cold vapor AAS:
Precision was calculated by
comparing the mean value for each pair
of duplicate samples.
Quality control was achieved
by measuring solution standards covering the range of concentrations found in
the samples.
Results
Important parameters derived
from the results of our
measurements are presented
numerically in Table 1 and graphically in Fig. 1. All figuress are presented in
µg/g (= mg/kg) dry weight. M=Mean, Md= Median, max.=maximum ccn., min.= minimum
ccn., SD = Standard deviation.
Table 1 Statistical parameters for heavy metal
concentrations in tobacco of cigarettes commonly smoked in different countries.
Cadmium,Cd
Cadmium concentrations vary
between 0.30 and 2.63 µg/g.
Highest contents occur in
Chinese brands (Md = 2.50, M = 2.22, SD = 0.55), the lowest in cigarettes from
India (Md = 0.37, M = 0.40, SD = 0.13).
German and Russian tobaccoes
occupy intermediate places with M = 1.00 and 1.11, respectively, the SD however
being much higher in the Russian
brands.
Canadian tobaccoes have the
lowest SD (0.09) with nearly identical M (1.58) and Md (1.57) and range between
1.45 and 1.82 µg/g.
Copper, Cu
The concentrations lie in the
range between 4.1 and 19.9 µg/g.
Canadian brands have by far
the lowest concentration (Md 4.8 µg/g) and a very low SD.
All other national brands
exhibit M and Md concentrations being about 2 to 3 times higher,
the highest contents to
be found in Indian and Russian brands,
followed by Chinese and German brands.
Lead,Pb
Lead concentrations vary
between a wide range between 0.90 and 6.12 µg/g.
Compared with all other
national brands Chinese cigarettes have by far the highest lead concentration
(M = 4.48, SD = 0.88 µg/g).
The mean content of all other
national brands lies within a narrow range between Canada (1.45), India (1.57),
Germany (1.62) and Russia (1.86).
Chromium, Cr
Chromium concentrations vary
between 0.29 and 1.71 µg/g.
Highest concentrations were
found in tobaccoes of German cigarettes (M = 1.26) the lowest in Indian and
Chinese products (M = 0.48 / 0.46 µg/g, respectively). Canadian and Russian
cigarettes have intermediate concentrations with M = 0.83 / 0.88µg/g, respectively.
Zinc, Zn
Amongst all heavy metals
investigated zinc concentrations show
the least differences between national brands. Mean concentrationss range
between 28.9 in Indian and 36.3 µg/g in German cigarettes.
Mercury, Hg
The concentrations range
between 0.02 and 0.11 µg/g. Mean concentrations are 0.03 for Canada and Russia,
0.04 for China, 0.05 for Germany and 0.06 µg/g for India. With the exception of
Indian brands the SD of all other
national brands is low.
Discussion of Results
Variation of cadmium
contents in tobaccoes of German cigarette brands within time
Our first aim, to receive new data on the cadmium content of tobaccoes in cigarettes commonly smoked in Germany (based on 9 brands - the same as in 1994 - with market proportions between 2.2 and 20.6 % in 1994) leads to the conclusion that this metal, to be considered as the most harmful amongst heavy metals, remained about the same between 1994 and 1998 with nearly identical values for mean, minimum and maximum concentrations (Table 2).
Year Min. Mean Max.
reference
Germany
1969 1.18 1.41 1.75 Szadkowski
et al. (1969)
1978 1.13 1.38 1.65 Müller
(1979)
1985 1.08 1.30 1.51 Müller
(1985)
1994 0.95 1.04 1.14 Müller
(1995)
1998 0.90 1.00 1.14 this
paper
Table 2 Development of cadmium concentrations in
tobacco of cigarette brands
commonly smoked in Germany with time
Range of cadmium contents
in cigarette tobaccoes from different countries
Table 3 compares analytical
data for cadmium in tobacco of cigarettes from different countries.The greatest
difference exists between tobaccoes from Greece and India (mean 0.35 / 0.40
µg/g, respectively) and China (2.22 µg/g), which results in a multiplication
factor of about 6. Austria, USA, Germany and Russia fall into an intermediate
range between 0.80 and 1.11 µg/g. Canada and China find their place in the
upper range (1.58 and 2.22 µg/g, respectively).
country Min. Mean Max. reference
Greece 0.21 0.35 0.85 Kalaitzoglou
& Samara (1999) 32 brands
India 0.30 0.40 0.73 this
paper 9 brands
Austria 0.26 0.80 1.38 Nitsch & Kalcher (1991) 12 brands
USA 0.89 0.99 1.09 Bell
& Mulchi (1994) 11 brands
Germany 0.90 1.00 1.14 this paper 9 brands
Russia 0.55 1.11 1.74 this
paper 9 brands
Canada 1.45 1.58 1.82 this
paper 10 brands
China 0.99 2.22 2.63 this
paper 9 brands
Table 3 Analytical data for cadmium in cigarette
tobaccoes from different countries
Significant
differences in heavy metal concentrations in cigarette tobacco from different
countries
A
simple explanation for a distinct concentration level of a heavy metal in
cigarette tobacco cannot be given.
There
are pimary factors which influence the heavy metal level already in the growing
tobacco plant: composition of soil and dust, application of fertilizers,
species of the tobacco plant itself, to which secondary factors have to be
added:
mixing
of different tobacco species differing in metal composition, treatment during
fermentation.
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Fig. 1 Statistical parameters
for heavy metals in tobacco of cigarettes commonly smoked in different
countries.
