Pulmonary Function and Symptoms in Herbal Tea Workers

study may have been due to the diJferences in dust concentrations for the diJferent cottons. An accurate adjustment for these diJferences cannot be made because only two closely spaced points on the doseresponse curve for standard cotton dust were obtained, and it may not be accurate to assume a similar slope for the dose-response to closed boll cotton dust even if the slope for standard cotton dust were known precisely. However, using a simple extrapolation based on the observed dose-response slope for standard cotton dust, response to SCBI and LCBR cotton dusts remained significantly lower than the response to standard cotton dust. The same adjustment applied to the response to rayon, results in a larger decline in FEV1 than observed with standard cotton exposure. Whether bract removal is important in reducing the biologic activity of closed boll cotton cannot be determined from this study. Likewise, although the correlation of endotoxin content and pu]monary function response was not significant, the inhaled dose of endotoxin may not be accurately reflected in measurements on random bulk samples. Analysis of airborne endotoxin from this and future studies may allow more definite conclusions to be made. Finally, whether the acute pulmonary function response to a six-hour exposure in nonbyssinotic subjects is a valid predictor of the potential of a given type of cotton dust to produce byssinosis or permanent pulmonary impairment after long-term exposure can only be determined from carefully controlled prospective studies. However, short-term exposure studies seem to be useful and safe in rapidly estimating the relative effectiveness of various experimental treatments in decreasing the biologic activity of cotton dust.

REFERENCES 1 Berry G, McKerrow C, Molyneux M, Rossiter C, Tombleson J. A study of the acute and chronic changes

Pulmonary Function and Symptoms in Herbal Tea Workers* Robert M. Castellan, M.D.; Brian A. Boehlecke, M.D.; Martin R. Petersen, M.S.; Tem.J D. Thedell, Ph.D.; and James A. Merchant, M.D., Dr. P.H.

0

ccupational respiratory disease caused by inhalation of dust generated during the manufacture of tea was first reported in terms of "tea factory cough" by Castellani and Chalmers. 1 Occupational asthma in a tea factory worker was later labeled as "tea maker's asthma" by Uragoda. 2 Ebihara8 described two persons

•From the Division of Respiratory Disease Studies, Natiowil Institute for Occupationaf Safety and Health, Morgantown, WV. Use of commercial names does not imply endorsement by the NIOSH. .Reprint requem: Dr. C~944 Cheamut Ridge Hood, Morgaratowra, West Virginia :4fltjf}5

CHEST, 79: 4, APRIL, 1981 SUPPLEMENT

in ventiJatory capacity of workers in Lancashire cotton mills. Br J Ind Med 1973; 30:.25-36 2 Merchant J, Lumsden J, Kilburn K, et al Dose response studies in cotton textile workers. J Occup Med 1973; 15:222-30 3 Batawi MA, Shash El, El-Din S. An epidemiological study on aetological factors in byssinosis. Int Arch Gewerbepath Gewerbehyg 1962; 19:393-402 4 Knudson R, Slatin R, Lebowitz M, Burrows B. The maximal expiratory flow-volume curve normal standards variability and effects of age. Am Rev Respir Dis 1976; 113:587-600 5 Olenchock S, Mull J, Boehlecke B, Major P. Cotton dust and complement In oloo. Chest 1981; 79:53S-55S 6 Roach SA, Schilling RSF. A clinical and environmental study of byssinosis in the Lancashire cotton industry. Br J Ind Med 1960; 17:1-9 7 Schilling RSF, Vigliani EC, Lammers B, Valle F, Gilson JC. A report on a Conference on Byssinosis. In: Proceedings of the XIVth International Congress on Occupational Health, Madrid. Amsterdam; Exerpta Medica, 1963:137-45 8 Douglas J, Zuckerman A, Ridgway P, Bouhuys A. Hista..mine release and bronchoconsbiction due to textile dusts and their components. Second International Conference on Respiratory Disease in Textile Workers. Alicante, Spain; 1968: 148-55 9 Cavagna G, Foa V, Vigliani E. Effects in man and rabbits of inhalation of cotton dust or extracts and purified endoto:dns. Br J Ind Med 1969; 26:314-21 10 Cinkotai F, Lockwood M, Rylander R. Airborne microorganisms and prevalence of byssinotic symptoms in cotton mills. Am Ind Hyg Assoc J 1977; 38:554-59 11 Merchant JA, Lumsden J, Kilburn K, et al. Pre-processing cotton to prevent byssinosis. Br J Ind Med 1973; 30:237-47 12 Bouhuys A, Schoenberg JB, Beclt GJ, Schilling RSF. Epidemiology of chronic lung disease in a cotton mill community. Lung 1977; 154:167-86 13 Merchant JA, et al. Byssinosis and chronic bronchitis among cotton textile workers. Ann Intern Med 1972; 76:423-33

whose illnesses, allergic rhinitis in one and asthma in the. other, were related to cultivating and harvesting tea. Several surveys of groups of tea workers have been reported. One revealed by questionnaire an excessive prevalence of chronic bronchitis and asthma.' Another reported shift reductions in FEV1 related to dust exposure. 5 Yet another demonstrated a chronic effect of tea dust exposure on expiratory flow rates.• We evaluated a potential occupational health hazard at an herbal tea processing and packing plant where black tea (the basis of the above-mentioned reports) is only one of dozens of raw ingredients processed. During a preliminary si~ visit, a NIOSH physician interviewed workers and reviewed data from the company's pulmonary function surveillance program. Because of frequent respiratory symptoms, including one case history strongly suggestive of occupational asthma, and because of objective documentation of shift decre-

INTUNATIOIAL COllFEIEllCE 011 BYSSlll• 81S

Uaedin Prepariq T-

Table 1--1~

Alfalfa

Eleuthro

Orange Leaves

Allspice

Eucalyptus

Orange Peel

Almond Powder

Fennel Seed

Papaya

Star Anise

Foenugreek

Passion Flower

Anise Seed

Ginger

Peony

Barley

Ginseng (Panax)

Peppermint

Blackberry Leaves

Golden Rod

Peppermint Oil

Black Tea

Golden Beal

Raspberry Leaves

Blueberry Leaves

Gotu Kola

Red Clover

Carob

Hawthorne

Rosehips

Cassia

Hibiscus

Rosemary

Cassia Oil

Hops

Rose Petals

Catnip

Lemon Grass

Sage

Chamomile

Lemon Mist Oil

Scullcap

·chicory

Lemon Peel

Slippery Elm

Clove

Lemon Verbena

Spearmint

Comfrey Leaves

Licorice Root

Spearmint Oil

Comfrey Root

Lovage Root

Strawberry Leaves

Crystal Malt

Matte, Green

Titia

Dandelion Leaves

Matte, Roasted

Yarrow Flowers

Dandelion Root

Nettles

Wild Cherry Bark

Elder Flowers

Orange Blossoms Vanilla Extract

maneuvers were recorded for each worker on an Ohio 840 waterless electronic spirometer. Each worker repeated the maneuvers after the worksbift on the same spirometer under the direction of the same technician, and performed at least &ve maneuvers at each session. Values were corrected to body temperature and pressure, saturated with water vapor (BTPS), and a "maximum envelope" flow volume curve was generated by computer. Normal prediction equations used for comparison were those of Knudson et al. 7 A modi&ed Medical Research Council questionnaire on respiratory disease was administered to each worker. Additional questions for chest tightness on particular days of the week were included. At the postshift sessions, subjects were asked whether they had wom any kind of dust mask during the shift and whether they had developed chest tightness during the shift. Symptoms were defined by answers on the questionnaire as follows: "chronic cough": cough on most days for as much as three months a year; "chronic bronchitis": production of phlegm from the chest on most days for as much as three months each year; and "dyspnea": shortness of breath while walking with people of the same age at an ordinary pace on the level, or with less exertion. Personal dust sampling for both respirable and total dust was done during the same worksbift as spirometry testing. General area dust measurement was performed with openfaced cassettes and vertical elubiators, and particle size distribution estimated with an Andersen nonviable cascade impactor. For analysis, workers were assigned to one of three exposure categories: low exposure (employees with offices located in the front of the building in which paclcaging was done); high exposure (bulk paclcagers and production workers from the milling and blending building); and moderate exposure (workers not in the other two exposure categories).

Winterberry Extract ments in pulmonary function, further investigation was undertaken.

Plant Proceases The plant receives nearly 70 different raw ingredients (Table 1) from throughout the world. Processing <><>curs in several steps. The dustiest processes (cleaning, milling, sifting, and blending) all take place in a single building. Blended materials are transferred to another building for packaging. Bulk packaging is done by manually scooping blended herbs, and small clouds of airborne dust were visible in the breathing zone of bulk packagers. In contrast, tea bagging is significantly less dusty. Blended material is pneumatically conveyed to a machine that automatically ha~ the tea. Workers attending the machine manually box the bagged tea. The offices are located in the front of the building where packaging is done. A door connects the office area with a break room, which is open to the production area. SURVEY METHODS

We conducted a cross-sectional survey of the entire worker popuJation. On return to work after a weekend off and before entering the workplace, forced expiratory

82S AMERICAN COLLEGE OF CHEST PHYSICIANS

IU:sULTS

Two hundred six of 213 employees participated in at least some part of the survey. Questionnaires and complete spirometry data were obtained for 173 persons. The employees were generally young adults, sexes were equally represented, and mean tenure of employment was less than two years (Table 2). Ninety-eight percent of the workers were white, with 38 percent current cigarette smokers and 32 percent exsmokers.. Prevalence of mask wearing on the day of the study ranged from zero percent of workers in the low-exposure category to 34 percent of those in the highexposure group. There was no attempt to qualify or quantify mask use. Although some workers wore particulate-removing half mask respirators with replaceTahle 2-ropuladon Profile

Exposure Category Low Moderate High Overall

Percent Male

Mean Tenure,

yr

62

30.1

40

2.2

112

27.8

58

1.3

32

27.3

41

2.1

206

28.3

50

1.7

No.

Mean Age,

yr

CHEST, 79: 4, APRIL, 1981 SUPPLEMENT

--

P(Om

0~

""uz ~ ""

40 30

0:: '1.

~'1.

:E

>-

N.S. N.S.

20 10

Cl)

Number

61 110 32

lDN MOO.HIGH Symptoms Chronic Cough

Exposure

61 Iii 32

able filters for much of the shift, many merely used a bandana pulled over the mouth and nose at various times during the workshift. Mean personal total dust concentrations varied by an order of magnitude between categories, from 0.15 mg/ms for low exposure to 13.79 mg/m 8 for high exposure, a statistically significant difference (P< 0.01). Mean personal respirable dust concentrations ranged from 0.09 mg/m8 for low-exposure workers to 0.66 mg/m 3 for high-exposure workers, also statistically different (P<0.01). General area total dust sampling, done for categories of moderate (mean= 1.00 mg/m8 ) and high (mean= 12.18 mg/m 3 ) exposure, correlated well with the personal sampling. Mean vertical elutriator levels were 0.37 mg/m8 for moderate and 3.25 mg/m 8 for highexposure areas. Airborne dust samples were taken by Andersen cascade impactor in the milling, sifting, and blending building. Approximately 50 percent by weight was less than lOµm in aerodynamic diameter, and about 25 percent was less than 7 µm. The prevalence of respiratory symptoms was analyzed by exposure category (Fig 1). High-exposure workers had significantly higher prevalence of chronic cough and chronic bronchitis than workers in the lowexposure category. Prevalence of dyspnea, on the other hand, was not different between exposure categories. Prevalence of chronic cough ranged from zero percent of nonsmokers in the low-exposure category to 73 percent of smokers in the high-exposure category (Fig 2). A dust effect was statistically significant among nonsmokers, but not among smokers. For chronic bronchitis, similar trends were found, but there were no statistically significant differences (Fig 3). Mean preshift spirometry results are shown in Table 3. Mean FVC and FEV1 were greater than 100 percent predicted in all exposure categories, with no statistically significant differences. Mean FEV1 /FVC ratios were greater than 0.80 for all exposure categories,

CHEST, 79: 4, APRIL, 1981 SUPPLEMENT

61 Ill 32

lDN Ma>. HIGH Chronic Bronchitis

Dlspnea

FIC11D 1. Symptom pxevalence sure category.

by expo-

also with no significant differences. Shift changes in FEV1 were determined by subtracting a subject's preshift value from the postshift value. Only the low-exposure group had a mean increase in FEV1 (0.1 percent of the preshift value). Moderate-exposure workers showed the greatest decrement (1.2 percent), but differences between the three

N.S

70

-0~

~ 50 z

""~ ""a:: ...J

N.S

'1.

e ::J

8 !J

~ a:: ~

u

N.S. 10

Nlrnber'

19 31 I 0

EJCPOU9 Ll:Ni MOQ HIGH SrnokklQ Slalus NMr Smokers

24 40 II lDli MCXl HIGH Cwrent Smolmrs

FIC11D 2. Chronic cough pnwa)ence by ~

and smoking status.

category

INTERNATIONAL CONFDENCE ON BYSSINOSIS 83S

-

:ie .!...

~

a: 40 0.

N.S. N.S.

(/)

F

N.S.

0

~

NS.

u

~

10

0

Number Exposur9

24 40 II

19 31 10 LON MOD. HIGH

Smoking Status

LON MOD. HIGH

Never Smoklers

Current Smokers

li'IGoBB 3. Chronic bronchitis prevalence by exposure category and smoking status.

groups were not statistically significant. Only one subject had a shift decrement in FEV1 of more than 10 percent. This was a bulk packager with a 14 percent fall who had been asthmatic since age ten years and had mild obstruction noted on baseline spirometry. Fourteen other subjects had FEV1 decrements between 5 and 10 percent. Exposure groups did not differ significantly in the proportion of subjects who had FEV1 shift decrements of 5 or more percent, and regression analysis revealed no signi&cant correlation (P = 0.37) of FEV1 shift change with personal respirable dust exposure. Nine workers had a pattern of chest tightness or breathing difficulty beginning at work on their &rst day back to work after a weekend off. All nine were from the moderate- and high-exposure categories, representing 7 percent of workers with completed questionnaires from these categories. None of these nine had previous occupational exposure to cotton, flax, or hemp dust. Seven were exsmokers, and two were never smokers. Twelve other workers, all but one from the moderateand high-exposure categories, had a pattern of chest symptoms developing on particular days of the week exposure

c,,,.,,,.,.

Tahle 3-Jfean Pra'hJ/I Pulnionarr hnedon

"1' Espoare

Exposure

Category Low

Moderate High

FVC,

FEV1,

No.

%Pred

%Pred

FEV1/FVC

57

106

107

0.83

107

109

111

0.84

30

110

111

84S AllEllCAfl COWIE OF CHEST PHYSICIANS

0.84

other than the first day back to work. Within the moderate- and high-exposure categories, 16 of 20 workers who had chest symptoms on particular days had both preshift and postshift spirometry. Seven with first-day-back-only symptoms had a mean increase in FEV1 of 0.3 percent. Nine who had a pattern of chest tightness on other workdays (but not &rst days) had a mean decrement in FEV1 of 3.0 percent. Neither of these shift changes was statistically different from a 0.9 percent mean FEV1 decrement of 104 workers who did not have symptoms on particular days of the week. On the day of pulmonary function testing, 10 percent of workers at risk had chest tightness with onset after entering the work site. The prevalence was statistically greater (P<0.05) for high-exposure workers (six of 29) compared with low-exposure workers (one of 47). Moderate-exposure workers had an intermediate prevalence, with ten of 102 workers developing chest tightness during that shift. The mean FEV1 shift change for workers in whom chest tightness developed during the studied shift (-3.4 percent) was a significantly (P< 0.01) greater decrement than that observed in workers

-

+3

+2 +I

CHEST

NO n•l59 0-+-~--------------

TIGHTNESS

YES n•l5

-I

~

z

-2

<(

0

-3 p(0.01

FmmlB 4. Mean FEV1 shift change and chest tightness d&-

veloping during the sbidy shift.

CHEST, 79: 4, APRIL, 1981 SUPPLEMENT

without chest tightness during work on that day ( -0.4 percent); (Fig 4). DISCUSSION

Our survey results indicate that chronic cough and chronic bronchitis prevalences were related to degree of exposure to herbal dust. Although spirometry results did not reveal a chronic effect of occupational exposure to herbal dusts, tenure of employment of all workers was short. It should be emphasized that workers in the low-exposure category, used as a comparison group, were not entirely unexposed. Many took breaks in a room that was contiguous with areas of the packaging production area, and about one third of them had previously worked in jobs in higher exposure categories. A pattern of first-day-back chest symptoms had not previously been reported to be caused by exposures to tea or herbal dusts. In fact, one published epidemiologic survey found no one with byssinotic symptoms among 85 workers in a tea packing factory. 8 Thus, it is interesting that we found dust-exposed ( nonofBce) workers at this herbal tea factory to have a 7 percent prevalence of a first-day-back pattern of chest symptoms. Although far less than the reported 20 percent to 40 percent prevalence in cardroom workers of cotton textile mills,9 it is in excess of the expected false-positive response rate for the same questionnaire reported by Merchant et a11 0 in a study of synthetic and wool textile mill workers. In the past two years, NIOSH interviewers have administered this questionnaire to more than 400 workers in nondusty occupations, with less than 1 percent positive for chest symptoms on the first day back to work (unpublished findings). The reporting of first-day-back symptoms may have been falsely elevated at the herbal tea factory because printed materials about byssinosis had been distributed by the company to its workers. (Having some familiarity with the term brown lung, some workers referred to their chest symptoms as "green lung," the color having been derived from the fine greenish-brown dust that tends to settle on production workers' clothes.) In fact, those with a history of first-day-back symptom pattern had an increase rather than a decrement in their mean FEV1 over the first shift of the work week. On the other hand, workers having chest tightness on the day of our survey did show significantly greater decrement in FEV1 than those without this symptom. No significant relationship was found between FEV 1 shift change and personal dust exposure. However, the ability of our survey to detect a relationship between dust exposure and shift decrement in FEV1 was limited because personal dust exposures as measured may not have reflected actual exposure for the numerous workers who wore masks of varying efficacies for various fractions of the shift. Also, a pulmonary function sur-

CHEST, 79: 4, APRIL, 1981 SUPPLEMENT

veillance program at the plant may have achieved its goal of eliminating persons with increased airway reactivity. Only seven of 14 workers referred to physicians in the year of this program's existence were still employed at the time of our survey. Regardless of this program, subtle migration of the most susceptible workers away from dusty jobs probably occurs. Another limitation of our survey is that, because all raw ingredients are not processed on any given day, we did not fully characterize all possible exposures at the factory. Also, owing to the very limited tenure of the workforce, effects associated with long-term exposure could not have been detected. In summary, symptoms of chronic cough and chronic bronchitis were related to herbal dust exposure. An unexpectedly high prevalence of respiratory symptoms occurring regularly on the first working day of the week was found by questionnaire but was not associated with decrements in baseline pulmonary function. Dust-exposed workers who had chest tightness or breathing dif6culty at work on the day of the study had a small, but statistically significant, decrement of FEV1 over the workshift. However, the risk of chronic impairment of lung function caused by prolonged exposure to herbal dust cannot be determined from this cross-sectional survey.

llEF.ERENa:s 1 Castellani A, Chalmers A. Manual of tropical medicine. 3rd ed. New York: William Wood & Co, 1919 2 Uragoda CG. Tea makers' asthma. Br J Ind Med 1970; 27:181-82 3 Ebihara I. Study on the inhalative allergy of ciliae of leaves: inbalative allergy of the ciliae of tea leaves. J Sci Labor 1975; 51:661-65 4 Uragoda CG. Respiratory disease in tea workers in Sri Lanka. Thorax 1980; 35:114-17 5 Al-Zuhair YS, Cinkotai FF. Ventilatory function in workers exposed to tea and wood dust. IRCS; International Research Communications System 1977; 5:190 6 Grandjean M, Hotz P, Lob M. Etude de la fonction pulmonaire chez les travailleurs de deux enterprises de conditionnement de dies, tisanes et epices, selon le temps d'exposition. Soz Praventivmed 1978; .23:289-90 7 Knudson RJ, Slatin RC, Lebowitz MD, Burrows B. The maximal expiratory flow-volume curve: normal standards, variability, and effects of age. Am Rev Respir Dis 1976; 113:587-600 8 Cinkotai FF, Lockwood MG, Rylander R. Airborne micro-organisms and the prevalence of byssinotic symptoms in cotton mills. Am Ind Hyg Assoc J 1977; 38: 554-59 9 NIOSH. Criteria for a recommended standard: occupational exposure to cotton dust. HEW Publication No. (NIOSH) 75-118, 1974 10 Merchant JA, Lumsden JC, Kilburn KH, et al An industrial study of biological effects of cotton dust and cigarette smoke exposure. JOM 1973; 15:212-21

INTUllATIONAL COllFDEllCE 011 BYSSlllOSIS 85S