1997;6:33-4Q 33 Tob Control: first published as 10.1136/tc.6.1.33 on 1 March 1997. Downloaded from Release of carbon granules from cigarettes with charcoal filters John L Pauly, Sharon J Stegmeier, Andrew G Mayer, Joel D Lesses, Richard J Streck Abstract Keywords: cigarette filter; charcoal; fibres; gas Objective~~-To inspect cigarettes with a Most (more than 95%) of cigarettes marketed triple granular filter for charcoal granules 1 5 on the cut filter surface and, if present, to today in the United States have filters. " We determine whether the charcoal granules believe that the smoker perceives the filter of a on the filter are released during smoking. cigarette to be both safe and efficient. Design—400 Lark cigarettes in 20 packs However, recent observations in our laboratory were examined individually by each of challenged this view. For example, we have observed the release of cellulose acetate fibres three investigators for the presence of 1 charcoal granules on the cut surface of the from cigarette filters.' These filter fibres were: cellulose acetate filter. Without removing (a) observed trapped between the cellophane the cigarettes from the pack, the filters wrapper and the unopened pack of cigarettes; were examined with a stereo zoom micro- (b) present in the residue at the bottom of scope for charcoal granules. The percent- packs; (c) discharged from the filter when ciga- age of cigarettes that had charcoal rettes were tapped from a height of 3.5 cm or granules was defined, and charcoal dropped from 15 cm; (d) liberated when the granules on each filter were counted. Ran- filter was touched to the mouth of a human domly selected cigarettes were then volunteer or the surface of a piece of bovine smoked by consenting adult smokers to liver; and (e) released when cigarettes were assess whether the charcoal granules were smoked mechanically. released during smoking. Lark cigarettes "We believe that cellulose acetate cigarette fil- were smoked with a conventional cigarette ter fibres pose an additional health hazard to holder that had been configured to contain the smoker because the fibres are released dur- http://tobaccocontrol.bmj.com/ an in-line membrane. After smoking, the ing smoking.4 The tar coated synthetic fibres, membrane was analysed microscopically resistant to biodegradadon in the human body, for charcoal granules and other compo- are inhaled or ingested and may therefore pose nents of the filter that had been released an additional health risk to the smoker.4 during smoking. In the course of our ongoing studies, the fil- ters of cigarettes with charcoal filters were Results—Charcoal granules were ob- examined microscopically, (In this paper we served in 79,8% (319/400) of the cigarettes have adopted the convention of using the terms examined. The number of granules per charcoal, activated charcoal, carbon5 and coal cigarette was 3.3 (SD 3.7). Gaps between in describing these types of cigarette filters, see the tipping papers—the wrapping papers ref. 12.) We report here that charcoal granules that surround the filter—were often seen are present on the cut filter surface, and within on September 30, 2021 by guest. Protected copyright. (70%? 242 (71); n = 400 cigarettes). gaps between the cigarette wrapping papers Further, the charcoal cavity was about (that iss between the plug wrap surrounding 60% empty. For all smokers (n ~ 8/8), the cellulose acetate filter tow and the papers charcoal granules were released during encasing the charcoal granules). We predicted smoking. The number of charcoal that during normal smoking behaviour these granules captured on the membranes was charcoal granules would be discharged from 22,5 (16.2) per cigarette. charcoal filters in such a way that they would Conclusions—Charcoal granules are in- be inhaled or ingested. corporated into cigarette filters to aid in Many investigators have reported that Department of removing toxins in cigarette smoke. In cigarette smoking is a complex behaviour with Molecular studies of Lark, a popular American ciga- numerous variables that are difficult to Immunology, RosweH 5 7 Park Cancer Institute, rette with a charcoal filter, charcoal gran- replicate mechanically. " To enable us to Buffalo, Hew York, ules were observed on the filter surface, extrapolate the findings more accurately to the USA and were released from the filter when the smoking population as a whole, our study was uly cigarettes were smoked. During smoking, conducted with consenting adults, who were S J Stegmeier A G Mayer the toxin-containing charcoal granules asked to smoke charcoal filter cigarettes using a ) D Lesses are inhaled or ingested, The specific cigarette holder that we had modified so as to RJ Streck adverse health effects of inhaling or contain an in-line entrapment screen. The Correspondence to: ingesting carbon granules have not been screen was selected and configured with the Jhn LPauSLP y PhD, addressed; nevertheless, the smoker, as an intent of capturing filter elements released pepartment of Molecular I gy, Roswell Park educated consumer, should be informed during smoking. ^aacer Institute, Elm and of the possible health risks. Moreover, because human smokers are indi- J-arlton Streets, Buffalo, New «* 14263, USAjemaB: vidualistic in the manner in which they smoke, [email protected] (Tobacco Control 1997;6:33-40) we concluded that it would be more instructive 34 Pauly, Stegmeier3 Mayer, Lessesi Sireck Tob Control: first published as 10.1136/tc.6.1.33 on 1 March 1997. Downloaded from if we did not control the individuals' normal gap, no charcoal (low); >1 gap, no charcoal smoking behaviour. We know of no other pub- (medium); and >1 gap, with charcoal in the lished studies that have used human subjects to gap (high). test cigarette filter integrity or defects. For ail tests, a formal measure of the degree of association (for example, agreement) of the Methods counts recorded by three independent observ- 10 SUBJECTS ers was computed using the K test. All protocols and procedures used in the human For comparison, other cigarettes of various smoking study were approved by the clinical popular American brands were included as investigations committee of the Roswell Park controls. These control cigarettes had filters Cancer Institute. Subjects were adult (5* 25 that did not contain charcoal. years of age) long term smokers who were smoking currently at least 20 cigarettes per day. MODIFIED CIGARETTE HOLDER The volunteers were informed verbally of the With the safeguards against contamination purpose and scope of this study. Thereafter, a (see below), a cigarette holder was used to signed and witnessed consent was obtained. All measure the release of charcoal granules from participants were compensated financially. charcoal filter cigarettes during human smoking. The efficiency of the holder and CIGARETTES USED entrapment device was qualified initially in Cigarettes analysed were Lark cigarettes. Lark repeated trials in which Lark and other brands cigarettes are manufactured by Liggett Group. of cigarettes fixed to the holder were smoked Lark cigarettes have a triple granular filter mechanically. composed of cellulose acetate fibres and A conventional cigarette holder (Denicotea; activated charcoal and have been described in Denicotea Co (Germany^ distributed by detail elsewhere.3 3'fi A recently published book Lane), purchased from a local retail shop, was provided a historical overview of the origin of first removed from its cardboard packaging. charcoal filters and the development of the fil- The cartridge of Denicotea crystals was ter on the^Lark cigarettes.9 An exploded view of removed and discarded. The cigarette holder a triple granular filter is illustrated in fig 1. was then soaked in 20% bleach for 30 minutes and rinsed with deionised water. This was fol- ANALYSIS OF FILTERS FOR CHARCOAL GRANULES lowed by a second wash with Palmolive deter- Many of the tests reported here were gent (Colgate-Palmolive Company, New York performed with 20 packs of Lark cigarettes City) and repeated rinsing in deionised water. which had been purchased locally (two packs After the cigarette holder had been dried in http://tobaccocontrol.bmj.com/ from each of 10 vendors). Each pack of Lark an oven at 56°C, an entrapment device was cigarettes received a code number, and was added. This device consisted of an 85x250 mm then opened carefully in the laboratory. The polyurethane sponge cylinder (product Nc top wrapper of each pack was cut off with scis- 1030; 1.016 density; 30 ILD; Foamax, Arcade sors. Without removing the cigarettes from the New York). Positioned on the upstream end o pack, the filter surfaces of the non-smoked the cylinder was a white, fine mesh, polyeste cigarettes were examined with a stereo zoom screen (FN 5720-010; cut off- 0.1 |im; Poly) microscope (Stereomaster; Fisher Scientific). ite). In our initial examinations, the filters of ran- The entrapment device was positioned in th domly selected cigarettes, with and without proximal segment of the two piece holdei charcoal filters, were inspected for the presence When a cigarette was positioned in the holdei of charcoal granules and the integrity of the the end of the cigarette filter was approximate! on September 30, 2021 by guest. Protected copyright. wrapping papers. For quantitative analysis, the 3 to 5 mm from the entrapment screen. Th stereo zoom microscope was adjusted to cigarette filter was not permitted to contact th permit viewing of the whole cut surface of the screen. The assembled smoking apparatus ws cigarette filter (15-fold magnification; xl.5 transported in a capped Falcon polystyrer objective and xlO ocular). At x8 magnification, tube (17x100 mm; No 2051; Bectoi the resolution was about 13.7 (im; at x40, the Dickinson, Franklin Lakes, New Jersey). resolution was about 7.4 |im (personal communication, Carton Optical Industries, SAFEGUARD AGAINST AIRBORNE CONTAMINANTS Tokyo, Japan).