Drug and Alcohol Review (r992) rI, 3-6

E D I T O R I A L

Come to where the flavour is: additives and pesticide residue in cigarettes

There is an old joke which suggests that Camel cigarettes are the only brand with a picture of the factory on the packet. Ironically, while camel dung has never been found in Camel or any other brand of cigarette, there is nothing in the Australian legal or regulatory system that would preclude it from being there. Unlike food, beverages and pharmaceuticals, there is no legislation in Australia to regulate the chemicals in cigarettes. In i988 , a major article appeared in the tobacco trade magazine tKorld Tobacco [x]. It rhapsodized about the virtues of adding chemicals to cigarettes to enhance 'flavour'. Among the dozens rec- ommended were those with alluring names like '4- hydroxyisophorone, salicylaldehyde, and 2,3,5- trimethyl pyrazine'.

The following chemical additives are just a sample of those patented by tobacco companies in the USA in recent years: diterpene glycoside, glycyrrhizic acid, benzodioxanones , 2,6,6-trime- thyl-alpha-(iso) propenyl-x-cyclohexane-I-metha- nols, x,3-cyclohexadiene-i-methanols , acetyl hy- drinacenes, acetyl indanes, heterocyclic-hydroxy- substituted carboxylate compound, 7-methyl-x-2- benzopyrene, cis-3-hexenal , and trans-2-hexenal. Additives are used in cigarette manufacture for a variety of purposes, including temperature control (to stop the cigarette going out between puffs and to prevent it burning too quickly), moisture retention, flavouring, and paper treatments. In x989, the Canadian Government required tobacco companies to tell them which chemicals were added to cigarettes. Shortly after that edict, Philip Morris withdrew from the Canadian market without disclosing any such information. In the UK, cigarettes (excluding the filter) can contain

additives up to o.I5% of the final product or 0.5% in the case of pipe tobacco [2].

Pesticide residues are another unheralded com- ponent of cigarettes. In x98i the National Health and Medical Research Council (NH & MRC) reported that "certain pesticide residues in Austra- lian manufactured cigarettes were at levels appre- ciably higher than those in overseas brands . . . . Mean levels of dieldrin and DDT residues in particular had been determined at o.o 9 parts per million (ppm) and 7-3 ppm respectively which, because of the amount absorbed from the smoke, constitutes cause for concern. Significant proportions of the tolerable daily intakes of these chemicals were likely to be attributable to this source in smokers." Background docu- ments showed the average level of DDT in Australian cigarettes sampled was 43 times higher than a sample of UK and US brands. Dieldrin in Australian brands was 3 ° times higher

[3]. The NH & MRC has done very little about this

since then. In November i983, its Pesticides and Agricultural Chemicals Committee (PACC) tabled a review of pesticides used on tobacco prepared by the Commonwealth Department of primary Industry. Far from being, as requested by the NH & MRC "a scientific investigation into the levels of potentially harmful residues in cigarettes" the paper was simply an updated listing of a I976 European Economic Community report, with local additions from Queensland and Victo- rian agricultural bulletins. In May I984 , the PACC 'noted' and discussed the document and concluded that current methods for setting maximum residue limits (MRLs) and detection of residues were

4 Editorial

'unsatisfactory' for tobacco. The Public Health Advisory Committee of the NH & MRC "noted that the issue had been raised as a result of consumer concern and that the PACC had been requested to provide advice". The minutes record that the PACC was "thanked for providing the information". After all this Committee paper shuffling and voting of thanks, no actions were recommended or appear to have been taken by the NH & MRC. The NH & MRC Secretary wrote in February i986 that "there is no routine testing of tobacco in Australia for pesticide residues. Testing has been carried out on an ad hoc basis although details are not available."

Tobacco plants can be attacked by a range of pests which may affect all stages of development, from seed-bed to storage after curing in barns and warehouses. A wide range of pesticides (herbi- cides, fungicides, insecticides, desuckering agents) are used on tobacco crops. At present, agricultural chemical manufacturers wanting to market a pesticide for use on tobacco in Australia are required by the Department of Primary Industry "to produce results of field trials and to show the level of residues of the original compound(s) and/or metabolites which occur in tobacco when the agricultural chemical is applied at the maxi- mum rate and concentration proposed in the label directions" [4].

Well and good. But this process has two disturbing aspects. Firstly, maximum residue lim- its are not set for agricultural chemicals in tobacco in Australia and so the submission of data by the manufacturers is not officially compared to any declared standard. If residue levels from field trials are required to be declared, presumably they are scrutinized against some de facto standard. Why have such unofficial standards not been formalized in Australia? Next, the manufacturers are able to carry out the trials for new pesticides themselves, totally unsupervized by anyone not employed by the very agrochemical companies seeking to gain financially by marketing a new pesticide. The consumer might well be entitled to conclude that pesticide use on Australian tobacco crops takes place in total absence of any standards, safeguards or routine reporting.

A I976 report by the Commission of the European Communities, 'Pesticide residues in tobacco and tobacco products' [5], remains the main reference on this subject. It identifies two

types of legal restrictions in the pesticide/tobacco area. There are restrictions for the use of chemicals on tobacco in the field and during storage and those that assign residue tolerances on traded tobacco or on tobacco goods as sold to the consumer.

The report comments that most countries have the first type; Sweden has only the second; while Argentina, Germany, Malawi, Zimbabwe, Swit- zerland, USA and Yugoslavia have both types either enacted or pending. Australia has neither type, or put another way, absolutely no standards or controls on what may be used or left on tobacco. The outstanding reason for this situation appears to be that health bureaucrats cannot bring themselves to class tobacco either as a food which would allow it to be subject to pesticide residue standards under food legislation, or to place it under controlled substances legislation by regard- ing it as the drug it is.

While the handful of countries listed above have safeguards on what pesticide residues their own domestic smokers can inhale, none appear to grant smokers in their export markets the same protec- tion. The lack of any uniform standards conceiva- bly results in leaf containing high levels of certain residue being channelled to those importing countries without standards like Australia. For example, an article in the tobacco industry journal Tobacco International in i983 cautioned that several countries now discriminated against leaf that contains excessive residue of MH (malaeic hydrazide), a sucker control chemical. West Germany has an MH limit of 80 ppm while US leaf in i982 averaged i3o ppm. The USA is the largest exporter of tobacco in the world, including to the Australian Market.

Australia imports much of its tobacco require- ments. In addition to manufactured cigarettes, in i984-9o Australia imported 64254 tonnes of tobacco (source: Australian Bureau of Statistics). Much of this came from Third World nations like Brazil (5074 tonnes), Malawi (9237 tonnes), Zim- babwe (7265 tonnes) and Thailand (4o96 tonnes) where agricultural standards and controls are often non-existent.

When tobacco is burnt, considerable amounts of pesticide residue are destroyed but many studies have shown that the agrochemicals and their thermally decomposed products (pyrolysis) can be transferred to the mainstream smoke that is drawn

Come to where the )qavour is 5

in by the smoker. A large body of published evidence has shown smoking to produce signifi- cantly elevated levels of pesticide in smokers when compared with non-smokers whose levels result from exposure through residue on food, and household and environmental exposure. It has been estimated that smoking one pack per day (the most common level in smokers) could produce an intake of o.o4-o.o 7 mg/day of total DDT. The Food and Agriculture Organisation and the WHO's joint Expert Committee on Pesticide Residues in Foods sets o.35 mg (men) and o.29 mg (women) as the 'acceptable daily intake' level for DDT. A smoker's additional intake of DDT could therefore be up to a quarter of their daily acceptable tolerance.

The NH & MRC statement focused on organo- chlorine residues like DDT which have been replaced by newer, less persistent compounds (organophosphorus insecticides in the I97OS and synthetic pyrethroids in the i98os ). But even scientists employed by the industry admit that the problem is far wider than abolishing the use of DDT. Two researchers from the University of Kentucky in the centre of the USA's tobacco belt have stated "Merely replacing the DDT-TDE residues with those of other toxicants cannot be accepted as a solution to the problem of excessive pesticide residues on tobacco" [6].

Some researchers have suggested that pesticide residue may be a critical factor in the development of cancer. One study found a significant associa- tion between cancer and concentrations of PCB (polychlorinated biphenyls) and DDE in subcuta- neous adipose fat. This study did not control for smoking, but the authors suggested smoking may be explanatory because smoke contains organo- chlorine compounds [7]. While organochlorines have not been officially used in some growing countries since the early 197os , analysis of Ontario leaf in 1986-88 reported considerable residues from this past use [8].

Of particular concern is the issue of elevated levels of pesticide residue in human breast milk. For example, a significant positive correlation was observed between smoking and the DDE content of human milk fat in I54 Canadian women [9]. A Pennsylvanian study of 55 human milk samples for presence of DDT found that the number of cigarettes smoked per day was one factor that accounted for 54 % of the variance on total DDT

levels [lO]. A 1971/72 study of human milk samples from 40 Queensland women (20 from Brisbane and 2o from Mareeba on the Atherton tableland) found ioo°/0 of samples positive for HCB (hexachlorobenzene), DDT and metabolites and dieldrin. In the Brisbane women the average DDT level was 8.6o ppm (range 3.26-2i.o) while the women from Mareeba had double this level, averaging i6.9o ppm (range 3.17-3o.9o) [H]. In Mareeba in the early 197os , large quantities of DDT were environmentally dispersed during the spraying of tobacco plants, causing atmospheric intake in local residents. This study did not consider whether the lactating women smoked.

In practice, there is no legislation in Australia for controlling any of the many hundreds of chemicals used by the world tobacco industry for pesticides, flavouring, combustion temperature control or paper treatment. The West German government extended the sort of legislated pesti- cide tolerances applying to fruit and vegetables to tobacco as far back as 1973 [6]. The prevailing attitude in Canberra can probably best be ex- plained by analogy with the view that the health hazards of smoking are rather like being in hell, with any additional risk from pesticide residue and additives being akin to simply turning the temper- ature up a degree or two [i2]. This attitude ignores the consumerist principle of the right to know: consumers have a right, acknowledged by .the United Nations, to product information that may be relevant to their purchasing decisions. The Federal Minister of Health should immediately commence investigations into why Australia seems unable to address this potentially important issue of public health that may affect the health of the 28% of adult Australians who still smoke.

References

Ix] Heyzer E. Best raw materials not essential for tobacco products market success. World Tobacco, March I988;4I-2.

[2] Froggatt P. Fourth report of the Independent Scientific Committee on Smoking and Health. Department of Health and Social Security. Lon- don: HMSO, i988:34.

[3] National Health and Medical Research council. Report of the 92nd Session, October i98i:18.

[4] Department of Primary Industry. Standing Com- mittee on Agriculture-Technical Committee on Agricultural Chemicals. Protocol of requirements

6 Editorial

for chemicals used on tobacco. Document PB 479, March 1985 .

[5] Commission of the European Communities. Pest- icide residues in tobacco and tobacco products, Vols x and 2. Information on Agriculture, No. r4, July x976 and 23 October i976.

[6] Dorough HW, Gibson JR. Chlorinated insecticide residues in cigarettes purchased I97o-72. Envir Entomol I972;i(6):739-43.

[7] Unger M, Olsen J, Clausen J. Organochlorine compounds in the adipose tissue of deceased persons with and without cancer: a statistical survey of so.me potential confounders. Envir Res I982;29:37I-6.

[8] Frank R, Braun HE, Clegg SB, Bayaery RP, Johnson W. Pesticide residues and metal contents in flue-cured tobacco leaf, Ontario, i986-88. Tobacco Reporter, April i99I~28-3I.

[9] Dillon J-C, Martin GB, O'Brien HT. Pesticide residues in human milk. Fd Cosmet Toxicol I98X~x9-437-42.

[to] Bradt PT, Herrenkhol RC. DDT in human milk. What determines the levels? The Science of the Total Environment i97616:i6i- 3.

[ix] Miller GJ, Fox JA. Chlorinated hydrocarbon pesticide residues in Queensland human milks. Med J Australia 1973;2:26x- 4.

[i2] Anon. Pesticides in tobacco "irrelevant to de- bate". Gold Coast Bulletin I99o i July It:49.

SIMON CHAPMAN Senior Lecturer in Community Medicine, University of Sydney, Igestmead Hospital, tFestmead NSlg 2t45, Australia