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CHAPTER 10 COTTON DUST EXPOSURE AND CIGARETTE SMOKING

Introduction 6 Influence of Cigarette Smoking on the Natural History of1 Bvssinosis. Cigarette Smoking Patterns Among. Workers Exposed to Cotton Dust Acute Effects of Smoking and Cotton Dust Exposure on Respiratory Symptoms Effects of Smoking and Cotton Dust Exposure on Pulmonary Function Tests Chronic Clinical Effects of Cotton Dust Exposure Mechanisms of Cotton Dust Lung Injury Inflammation (Bronchitis) Airways Constriction Chronic.Inflamrnatory Lung Destruction Cotton Dust Exposure and Mortality From~ Respiratory Disease and Lung.Cancer Control of Cotton Dust Exposure Summary and Conclusions

Yam pmGUCUon Slashing/Wesving Pl6p9rfiGGp Mistguaneows FIGURE: 1.-Byssinosis prevalence by work area and raw material use NOTE Avevage prevelPoce mttan. 6.2 percent; ceUonlsyntheiq 4 4 pprcent. 5OUECE:Imtlus enE Suh (1973). relationship to cigarette smoking is discussed in greater detail later in this chapter. Influence of Cigarette Smoking on the Natural History of Byssinosis Cigarette Smoking Patterns Among Workers Exposed to Cotton Dust The smoking patterns of cotton dust exposed workers have been reported by a number of authors and are presented in Table 1. In summary, current studies show that male cotton workers tend to smoke to a greater degree than do female cotton workers. Male textile workers in Western Europe and in Canada smoke with 404

tA TABLE 1.-Continued Study Number and type of populatiou Smoking cheracterieti® (percent) Cummenfe Imbue and Suh 10,133 ontton worke re, Men 78 Smokers include (1973) _ North Carolina - Women 43 ever smoked I cig/day for 1 Y. Berry et al. 14 cotton and 2 maamade Men 75.6 Former emokere (1974) fiber mills, Grest Britain Wamen 56.5 not reported Zuekin et n1. Wool workers and controls Workere Men 47 (1976) Women 0 Controle Men 65 Women 0 Khogali 271 ginnery workers, Sudan SM Alrnuet 1/2 (1976) 36.5 emokem enid smoked <6 cige/day Jones et al. (1977) 153 cottonmfll workers, southeast United States Card and weave room warkere, South Carolina E000Tti0e Men Women SM/ER 70 SM 18-61 15-3.6

TABLE 1.-Prevalence of smoking in studies of cotton workers Study Number and type of population Smoking characteristics (percent) Schreg and GuBett (1970) 509 cotton textile workers SM 38 EX/NS Kari-Koekinen and 987 female cotton workers, 16.9 83.1 Hirvonen (1970) Finlaud Age 17-29 39.8 30-39 141 40-09 9.0 60-46(1 5,0 Merchsnt, 7tiburq et al. (1972) 436 cottonaynthetic blend workere, North Carolina SM 64,7 SX 12.0 NS 33.3 Kilburn, Rflburn 1,046 female textile SM et el. (1973) worken, North Carolina Sym wool wwkere 45.2 - Cottnnmill worken 35.8 Srymczykiewia et 637 men, 2,690 women Men 80.5 M. (1970) Women 8.9 Pox at al, Cotton wnrkets, 35 mills, SM NS EX (1973) Great Britain 62 31,6 6.3 (7p/day 1-14 38.2 15-24 21 >24 2.8 zoootVoa Commentn Percent emuking <1 pack/day not arailsble >639a began emaking at 15-19 years of age

TABLE 1.--Continued Study Number and type of population Smoking characteristics (percent) Commenta Barm®n 70 cottonmill wurkere SM EX (1979) Men 44 28 Women 58 Sperke and Peters Ccttan duztezpooed worken Men 44 28 (1980) Women 56 - Grimard and Adams Tertile worke., Cznede Men 76.8 (1981) Women 60.4 Beck et al. (1982) 118 male and 162 female cotton t<rt8e workerz Men Worken 27 Controls 16 Wumen Workers 31 Controls 43 NO'Ck: SM=Smokeq EX=Ps.moker; NS=Nunemoker.

i Ptlmer et al. 203 gin workere SM EX NS (1978) Ginnees 51.1 25.5 23.4 (16.0)' (9.6) Pree®nen 57.1 19.1 23.8 (7.3) (4.1) Othere 456 15.1 39.4 (15.3) (8.01 Controle 52.3 192 28.5 (11.4) (9.1) Bouhuye et al. (1979) Textile wnrkere, aged Z45, South Cerolina Women Carding SM 18 EX 14 NS 68 Spinning 20 10 70 Prepering 17 14 69 Weaving 20 10 69 Othes' 15 11 74 Men C¢rding 26 M 26 Spinning 37 45 18 Preparing 50 42 g Weaving 38 37 18 Othem' 20 35 30 donee et sl. (1979) Cutton and wool/aynthetie mill wockere Mill 1 SM' 52.8 NS 47.2 Idil12 66.9 33.1 Mil13 64.8 35.2 ),fill4 38.0 62,0 ~ I ~ f'000IV0B '( )=mepv peck-ycere (1 pk/dey/yeei) 'Includes cloth room workets and miecelleneous job rategoriee 'Smokem include esamoke~

Introduction Exposures to cotton, hemp, and flax dust have been associated with two acute pulmonary responses: irritant (industJrial)~bronchitis and chest tightness (byssinosis). These symptoms, often, accompanied by reduction in lting function, have occurred in 2 to 30 percent of cotton textile workers within hours of resuming exposure following a weekend or holiday (Schilling 1956; Morgan et al. 1982). These elements of the acute cotton dust.pulmonary response may not occur together, and mayrepresentsesponses of distinct pulmonary mecha- nisms. The exposure variables or host characteristics that lead to cough rather than to bronchoconstrictiom are currently under careful study (Hogg and Eggleston 1984). The effects of cigarette smoking upon these different responses is also incompletely under- stood. In the manufacture. of cotton textiles, cotton dust exposure occurs most intensely when the tightly packed: bale is opened and when abrasive crushing and carding removethe "trash" (plant bracts and other parts, dirt, bacteria, and fungi) and align the fibers for spinning (IGideom and' Johnson 1978). Normally, as the cotton fibers are spun, twisted, and woven into cloth, progressively less dust is generated. By the time cotton cloth is processed, the procedure is practically free of cotton dust (Kilburn 1983). Cross-secfional studies have shown that byssinosis prevalence is greatest among cotton textile workers in the dusty preparation jobs (e.g., carder, stripper, or grinder) (Figure 1). Byssinosis prevalence has been related to the.duration of cotton dust exposure, to the quality of the raw cotton, and to the levels of lint-free cotton dust (Molyneux and Tombleson 1970;. Merchant,. Lumsden~ Kilburn, 0'Fallon et al. 1973b; Kamat et a1. 1981). At a cotton dust level of 0.2 mg/m' (lint-free dust of approximately 15 µm or less), approximately 15 percent of the cotton textile workers have some grade of byssinosis (Merchant, Lumsden, Kilburn~ O'Fallon et a1L 1973b). While a smalli sex-specific effect (male disadvantage) has been noted (Berry et al. 1974), no age effect has been shown after adjustment for exposure (Merchant, Lumsden, Kilburn, O'Fallon et al. 1973b; Berry et al. 1974). Cigarette smoke interacts with cotton dust exposure in cotton textile workers and has been associated with increased byssinosis prevalence.and severity (Berry et al. 1974). The frequency of byssinosis has been eloselycorrelated with the presence of chronic bronchitis, and both symptoms have been associated'with ventilatory impairment (Imbus and Suh 1973): Cross-sectional studies have correlated cotton dust exposure with two components of ventilatory impairment: reduction in the baseline level of forced expiration and reversible loss of function across a work shift. The relationship of byssinosiss and bronchitiss with ventilatory impairmentt and its 403

TABLE 2.-Prevalence. (percent) of byssinosis in nine exposure groups Exposure. (yr) Number in group Observedl prevalence Prevalence adjusted for age Prevalence adjusted for age, miil'type, and sex U-4 305 5.2' 8.8 8.0'. 5-9 10-14 155 168 23.3 29.01 20.5 22.3 19.2 21.0 1 fr 19 187. 368 '. 29.5 - 27:5 26-24. 117. 36.8'. 30.9 31.1 2529 115 43.5 40.2 42.4 30-34 94 30.R 30.2 35.1 35-39. 99 35.4 36.5 414 >40 119 336'. 37.7 418 SOI.'RCE: Nolmevx and Tcmbleson f1970). TABLE 3.-Age-adjusted association of bronchitis and smoking, by byssinosis status and sex Brnnchitis Brnnchitis Chi square end! with byssinosis withuut Hyssino.sl.s odtls ratio for the associatfon of $maker N' Present Absent. . N Present Absent smoking/brnnchitls' Yea No Yea No Chi 6quare':. Odds.RBtio'' Chi Bqunre'r. Odds RStio'! ' Men 127 55%. 45% 301 46% 54% %°=15.20 33 55% 45% 105 21% 79% OR=2.28 (p <0 0©01) Women 125 48%. 52% 322 31% 69% X'=21.10 78 33% 67% 268 16% 84% OR=216 (p<0-oW11 X'=2:83 X'=36.8 0R=149 0R=263 (p=0.09) (p<0.0001) X'=36:3 OR=2.21 (p<0.OW1) ' WeiBhtM by Mantel-Ilaenszel techni4Ve for hysnnmsu freqVenq. ' Weighted by M1fantel-HaPns..rl tArhniqVe fnr cex distrihutinn. ' W.yhted by M1fxn~el-Hxenvr] (achniyye fur fleyuenuy uf Luth by-nueu snd sex. BOURCEMalyneux snd Tomblesun (1970)) smokers' than among nonsmokers or exsmokers of bothh sexes; however, these differences were not st'atisticalily significant (Berry et al. 1974). 411 11

greater frequency than do American workers, with many studies showingg the proportionof smokers to be we1L over 70 percent. Acute Effects of Smoking and Cotton Dust Exposure on Respiratory Symptoms Thee symptoms oi Monday chest tightness begin gradually,. 3 or 4 hours after the cotton textile worker returns to work. A dry cough and shortnesss of breath on exertion frequently accompany the sensation of chest tightness. However, the physiologic reaction associated with Monday chest tightnesss is not confined to the chest. A low grade temperature, a 20 to 30 percent increase in the peripheral white blood cell (polymorphonuclear leukocyte) count, and a general malaise have been frequently reported. These systemic symptoms suggest the presence ofl a host inflammatory response; however, the relationship between these.syst'emic symptoms and the symptom of chest tightness is not we12 defined. By 1936, an association had been recognized between Monday chest tightness and detectable loss of ventilatory capacity and increased breathlessness (Prausnitz 1936). Recognition that in sus- ceptible cotton mill workers, Monday chest tightness may be followed by permanent respiratory disability led to the evolution of a standard byssinosis case definition. Schilling and colleagues (1ig55) developed: specific questions concerning. Monday chest tightness,for the British Medical Research Council's respiratory symptom survey questionnaire (British Medical Journal 1960). A positive.response to the standardized questions regarding Monday chest tightness de- fined the presence of byssinosis. Molyneux and Tombleson (1970) conducted! one of the first prospective studies.of byssinosis. At the initial examination, these investigators interviewed 11,359 workers from 14 cotton spinning mills and 227 workers from 2 manmade fiber spinning millsin Lancashire, United Kingdom. Followup examinations were conduct- ed at 6-month intervals over 3 years, from 1963 to 1966. Byssinosis and bronchitis prevalence were determined by the use of the Medical Research Council's questionnaire on respiratory symptoms (British Medical Journal 1960), to which the Roach and Schilling (1960) questions on chest tightness were added. Byssinosis wass graded as follows (Molyneux and Tombleson 1970)1? Grade 0: No evidence of chestt tightness or breathing diffi- culty on the first day of the workweek Grade 1/2: Occasional chest tightness on Mondays ' Nbte: OeHer investigaturs.have used grade 0 to.ind'.catc rhe absenrc of symptoms and grade 3 bvssinosu to indiceie the prese of chronic uhevuctive pulmanary dl:...e IfY)PIbItlnnhnyv en al 1969t How a r, this category would also mclnd& the chronic ubsnructive .pulmonary dlner+e tHnt «curs secondary.w.c,arecte smoking smngcottamworkes; slnceCOPD« rsfre9uenalyinalgarettesmukers.notexposed1tocottondust,thiscaugnry is not'speciic for disease related to cotton dust expasure. 409 11