Download - Occup Med (Lond) 1996 Lam 351 5
-
7/24/2019 Occup Med (Lond) 1996 Lam 351 5
1/5
Occup. Med. Vol. 46, No. S, pp. 351-355, 1996
Copyright @ 1996 Rapid Science Publishers for SOM
Printed in Grea t Britain. All rights reserved
0962-7480/96
Smoking and exposure to
occupational hazards in
8^304
workers in Guangzhou, China
T. H. Lam ,* C. Q . Jiang,*
W. W.
Liu,
1
W.
S . Zhang,*
J. M . He* and C. Q. Zhu
f
*Department of Comm unity Medicine, The University of Hong Kong,
Patrick Manson Building South Wing, 7 Sassoon Road Pokfulam,
Hong Kong; ^Guangzhou Occupational Diseases Prevention and
Treatment Centre, Huang Po Dong, Guangzhou 510420, China
This cross-sectional study aimed to describe the pattern of smoking in relation to
occupational
hazard
exposure in a working population in Guangzhou, China. In
1994,
data on smoking and occupational hazard exposure from occupational health
records of 8,304 subjects aged 35 years or older from 47 randomly selected factories
were studied. About 49 of the men and 55 of the wome n were exposed to dust,
chemicals or other hazards. The prevalence of smoking was 56.1 in men and 2.0
in women. The prevalence of sm oking in men was higher in those w ho were younger,
with primary education or who were workers. In women, those who were older, with
primary education or in management jobs had higher smoking prevalence. In men
and women, subjects who were exposed to occupational hazards had higher smoking
prevalence: the highest (71.6 ) was found in male workers expose d to dust. Urgent
tobacco control measures are needed to prevent the epidemic of smoking-related
and occupation-related diseases in the workplace in China.
Key
words:
China; occupational hazards; smoking.
Occup. Med. Vol. 46, 351-355, 1996
Received 20 M arch 1996; ccepted in final form 18 June 1996
INTRODU TION
The high prevalence of smoking and the increasing
incidence of mortality attributable to smoking in China
is a major public health problem locally and globally.
1
While most studies on smoking are usually published
in the Chinese literature, a few have recently appeared
in international journals and have aroused much
concern and interest.
2
4
In the field of occupational health in China, the m ain
concern is with exposure to occupational hazards;
smoking is often not a priority for health promotion
or protection in the workplace. There are few reports
which focus specifically on smoking prevalence in
relation to exposure to occupational hazards in the
working population. A study in a large petrochemical
complex in Shanghai showed that smoking was posi-
tively associated with sick leave after adjustment for
age,
alcohol consumption and exposure to chemicals.
Correspondence and reprint requests to:Prof. T. H. Lam, Department
of Community Med icine, The University of Hong Kong, Patrick Manson
Building South Wing, 7 Sassoon Road, Pokfulam, Hong Kong. Tel:
(+852) 2819 9287 or (+852) 2819 9280; Fax: (+852) 2855 9528.
However, the prevalence of smoking in the men
exposed to chemicals was similar to those who were
not exposed (80% compared with 79%).
5
A study on
byssinosis in Guangzhou showed that 67.6% of the
men in two cotton factories smoked, compared with
61.9% in control workers who had no history of
exposure to dust or other toxic substances.
6
Because
of the small number of woman workers who smoked,
no further analysis on female smoking patterns was
possible in both studies.
This study aimed to describe the pattern of smoking
in a working population aged 35 years or older in
relation to their exposure to occupational hazards and
other demographic variables.
METHODS
In 1 988, the 'Guang dong Province Lab our Safety and
Hygiene Regulations' were enacted by the Guangdong
Province People's Congress. From 1990-1992, under
the direction of the Guangzhou Occupational Diseases
Prevention and Treatment Centre (GODPTC), an
byguestonNovember4,2015
http://occmed.oxfordjournals
.org/
D
ownloadedfrom
http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/ -
7/24/2019 Occup Med (Lond) 1996 Lam 351 5
2/5
352 Occup. Med. Vol. 46. 1996
Occupational Health Surveillance Record System was
established basedon theregulations.T he aimwasto
establish two main types of records: (1) Individual
Worker's Health Surveillance Record(a20 page record
book) and (2) Industrial Hygiene Records (13 data
forms),
forall factories ofcounty levelorabove. The se
records were designed by the GODPTC. Occupational
health surveillance teams were formed
by
medical
and
hygiene personnel
who had
undergone
a
training
programme specifically organized
for
establishing
the
record system. Allworkers were medically examined
and were classified into exposed and unexposed
categories. Their demographic characteristics, work
history, medical history and smoking history were also
recorded in their individual records. Those with
abnormalities detected were followed-up andreceived
advice
or
treatment
as
approp riate. Workers classified
as exposed
to
hazardous substances were
to be
exam-
ined annually.
Industrial hygiene measurements were recorded
for
each factory and were evaluated to identify areas which
needed improvements. Advice onim provementswas
given, followed
by
further evaluations.
By the end of
1992 when
the
record system
was
completed,
860
factories
and
about 400,0 00 workers were included.
This covered
84 of all
factories
and 81 of all
workers eligible. Because informationinthe individual
worker's records was not computerized and there were
no resources to do so,detailed analysis of workers'
data, such as the prevalence of smoking, werenot
available.In 1994,the present study wasinitiatedas
a pilot study
to
plan
for the
setting
up of a
cohort
to
study the effect of smoking and occupational ex posures
on mortality. Factory doctors from
47
randomly
selected factories were requested
to
retrieve
28
items
of information, including demographic characteristics,
smoking history (amount smoked per day andyears
of smoking), occupational exposure category (e.g.
dust, chemicals, physical and other hazards, without
specifying thenature of the substances) andcommon
diseases detected, from therecordsofall workers who
were aged
35
years
or
older when the record was first
established, onto standard data retrieval forms.
T he
lower
age
limit
of 35
years
was
chosen because
the
cohort
had to
include older workers
to
increase
the
yield of mortality in future follow-up studies (there
were not enough resources to include youngersub-
jects).
The response rate of thefactory doctorswas
100%.
The data were entered
and
checked
by
using
EPI-
I N F O
and
a n a l y z e d
by
S P S S - P C . S t a t i st i c a l
procedures used included
2t e s t
> Fisher exact test,
-test, analysis ofvariance,and the Coxproportional
hazard model. The latter wasused to estimate the
prevalence rate ratio (P RR ) for smoking after adjusting
for other factors.
7
Two factories (with
a
total
of 324
workers) were
randomly selected from
the 47
factories
for
double
data retrieval
and
entry
and the
agreement
was
over
98%.
Smokers were defined as those who smoked atleast
one cigaretteperday. As there werefewoccasionalor
ex-smokers (only 30 subjects), they were classifiedas
non-smokers.
RESULTS
A totalof8,304 persons aged 35orabove, 4,637 men
(55.8%)and 3,667 women (44.2%), from 47 factories
were included. The distribution of the factories by
nature of industry was: light industry, 17; mechanical
and electrical, eight; chemical, six; pharmaceutical,
three; packaging, three; textile, three; construction
materials, two; electronics, one; fuel, one; metallurgy,
one;
others, two. Twelve
of the
factories were under
the GODPTC and the rest were from the eight district
anti-epidemic stations of Guangzhou. Each district
contributed threeto seven factories.
Table
1
shows
the
demographic characteristics
of
the sample. About 49%
of the men and
55 %
of the
women were classified
as
subjects exposed
to one or
more occupational hazards.
The
commonest occupa-
tional exposure wastochemicals, followed by physical
factors (e.g., noise) anddust (mainly silica, cemen t,
welding and organic dusts).
Table 1
.
Demographic character ist ics
of the
sample
Age (yrs)
3 5 - 3 9
4 0 - 4 4
4 5 - 4 9
50 -54
5 5 - 5 9
60 -64
65 +
Education (missing
Primary
Secondary
Post-secondary
Male
(n= 4,637)
No .
1,127
1,179
91 8
89 5
44 1
50
27
I 166
1,149
2,989
415
Marital status (missing
18
Single
Married
135
4,489
Occupation (missing40
Management
Workers
1,369
3,246
Occupational exposures (missing
Dust
Chemicals
Physical factors
Mixed exposure*
Other factors*
No exposure
390
63 7
477
121
750
2,260
24.3
25.4
19.8
19.3
9.5
1.1
0.6
25.2
65.6
9.1
2.9
97.1
29.7
70.3
2)
8.4
13.7
10.3
2.6
16.2
48.8
C
No .
1,529
1,284
63 2
159
28
17
18
1,269
2,195
121
106
3,556
68 7
2,962
23 8
51 7
19 0
45
65 2
2,025
Female
n
=
3,667)
41.7
35.0
17.2
4.3
0.8
0.5
0.5
35.4
61.2
3.4
2.9
97.1
18.8
81.2
6.5
14.1
5.2
1.2
17.8
55.2
'Mixed exposures were exposures tomore thanone of thefactors abo ve;
other factors included biological, radioactive
and
other less w ell-defined
factors.
byguestonNovember4,2015
http://occmed.oxfordjournals
.org/
D
ownloadedfrom
http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/ -
7/24/2019 Occup Med (Lond) 1996 Lam 351 5
3/5
T. H. Lam
et
a/.: Smoking and occupational hazards in China 353
Table 2. Prevalence of smoking in men and women
Age (yrs)
3 5 - 3 9
4 0 - 4 4
4 5 - 4 9
5 0 - 5 4
5 5 - 5 9
60 +
Education
Primary (< 6 yrs)
Secondary (6-12 yrs)
Post-secondary (12+ yrs)
Marital status
Single
Married
Occupation
Management
Workers
Occupational exposures
Oust
Chemicals
Physical factors
Mixed exposure
Other factors
No exposure
All subjects
Male
Wo.of smokers Prevalence
64 2
67 2
531
52 4
21 5
16
x
2
70 5
1,679
184
x
2
71
2,524
. 3
69 0
1,897
x
2
276
35 7
29 3
83
35 2
1,238
*
2
2,600
57.0
57.0
57.8
58.5
48.8
20.8
= 52.7, df = 5, p< 0.001
61.4
56.2
44.3
=
36.1,
df =2 , p< 0.001
52.6
56.2
t
2
= 0.7, df = 5, p
0.4
50.4
58.4
= 25.3, d f= 1 . p < 0 .001
70.8
56.0
61.4
68.6
46.9
54.8
= 74.4, df = 5, p < 0.001
56.1
X
2
= 2737.0,
Female
No. of
smok rs
Prevalence
33
20
10
10
1
1
x
=
32
41
1
x
2
2
73
x
2
20
54
x
2
10
34
7
1
1
22
x
=
75
df
1, p < 0.001
2.2
1.6
1.6
6.3
3.6
2.9
17.0,df = 5, p = 0.004
2.5
1.9
0.8
= 2.6, df =2 , p = 0.27
1.9
2. 1
=
0.01,
df
= 1 ,
p = 0.9
2.9
1.8
= 2.8, df =
1,
p = 0.9
4. 2
6.6
3.7
2. 2
0.2
1.1
82.0,
df = 5, p < 0.001
2.0
Th e prevalence of smoking was 56.1% in men and
2.0%
in women (Table 2). The prevalence of smoking
in men was the highest in those who were younger,
i.e. aged 35-54 years (57-59%), with primary educa-
tion (61%) and who were workers (58%). Although
the prevalence of smoking in women was low, some
notable differences were obvious. The highest preva-
lence of smoking was seen in older women. Although
not statistically significant due to small sample size,
the management personnel had higher smoking preva-
lence (2.9%) than the workers (1.8%) but there was
a similar decreasing trend of smoking with increasing
educational level.
In relation to occupational exposures, the highest
prevalence of smoking in m en was found in those who
were exposed to dust (71%). In women, it was found
in those exposed to chemicals
(6.6%),
followed by dust
(4.2%).
In Table 3, the increase in risk of smoking was first
estimated by the crude PRR which showed that, in
men, increased risk of smoking was associated with
younger age, lower education, being a worker and
being exposed to dust. After adjusting for each other,
the results were similar. After stepwise p roc edu res,
only age, education and occupation al exposures
remained in the final model. The adjusted PRR's in
the stepwise model were similar to those in the model
which included all five variables and are not reported
here.
In women, re-grouping was necessary for age and
education because of the small number of smokers.
The crude PRR showed that increased risk of smoking
was associated with older age, lower education and
exposure to chemicals and dust. After adjustment, the
results were similar. After stepwise proc edur es, the two
factors remaining in the model were age and occupa-
tional exposures.
In Table 4, after breakdown by occupation and ge nder,
the group with the highest prevalence of smoking was
identified: 71.6% of workers exposed to dust were
smokers. With the exception of female workers, the
subjects exposed to dust had the highest prevalence
byguestonNovember4,2015
http://occmed.oxfordjournals
.org/
D
ownloadedfrom
http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/ -
7/24/2019 Occup Med (Lond) 1996 Lam 351 5
4/5
354 Occup.Med. Vol.46, 1996
Table 3. Crude and adjusted prevalence rate ratio (PRR) for smoking in men and women
Age (yrs)
Male: 60+
55-59
35-54
Female: 35-49
50+
Education
Post-secondary
Secondary
Primary
Marital status
Single
Married
Occupation
Management
Workers
Occupational exposures
No exposure
Dust
Chemicals
Physical factors
Mixed exposure
Other factors
Crude PRR
1.00
2.35
2.77
1.00
1.27
1.38
1.00
1.07
1.00
1.16
1.00
1.29
1.02
1.12
1.25
0.86
(95 Cl
(1.41-3.90)
(1.69-4.53)
(1.09-1.48)
(1.18-1.63)
(0.84-1.35)
(1.06-1.27)
(1.13-1.47)
(0.91-1.15)
(0.99-1.27)
(1.00-1.56)
(0.76-0.96)
Male
Adjusted PRR (95 Cl)
1.00
2.35
2.77
1.00
1.19
1.32
1.00
1.10
1.00
1.03
1.00
1.23
1.01
1.07
1.21
0.86
(1.41-3.90)*
(1.69-4.54)*
(1.01-1.41)*
(1.10-1.59)*
(0.86-1.39)
(0.93-1.14)
(1.07-1.40)*
(0.90-1.14)
(0.94-1.22)
(0.96-1.51)
(0.76-0.96)*
Crude PRR
1.00
2.96
1.00
1.39
1.00
1 .09
1.00
0.63
1.00
3.87
6.05
3.39
2.05
0.14
Female
(95 Cl) Adjusted PRR (95 Cl)
(1.59-5.48)
(0.88-2.20)
(0.27-4.43)
(0.37-1.05)
(1.83-8.17)
(3.54-10.35)
(1.45-7.94)
(0.28-15.17)
(0.02-1.05)
1.00
2.92
1.00
1.59
1.00
0.95
1.00
0.53
1.00
3.90
6.81
4.23
2.46
0.15
(1.50-5.65)*
(0.97-2.61)
(0.23-3.86)
(0.30-0.94)
(1.79-8.50)*
(3.96-11.71)*
(1.79-9.99)*
(0.33-18.29)
(0.02-1.09)
These remained statistically significant after stepwise procedures. In the final stepwise model: in men, marital status and occupation were dropped and in
women,
education, marital status and occupation were dropped.
Table 4. Prevalence of smoking in management and workers by occupational exposure and gender
Male
Female
No. of
smokers
30
63
18
16
16 3
400
Z
2
= 10.6
245
294
274
67
18 9
827
X
2
=
58.1 ,
Prevalence
65.2
58.3
43.9
61.5
46.8
50.0
, df = 5, p=0.06
71.6
55.7
63.3
70.5
47.1
57.2
df =5, p < 0.001
No. of
smokers
Prevalence
4
5
1
0
1
9
2 tailed:
6
28
6
1
0
13
2 tailed:
16.7
6.8
6. 3
0
0. 7
2.1
Fisher exact test,
dust vs. no exposure, p =
0.003
2.8
6.4
3.4
2.4
0
0.8
Fisher exact test,
dust vs. no exposure, p - 0.02
Management
Dust
Chemicals
Physical factors
Mixed exposure
Other factors
No exposure
Workers
Dust
Chemicals
Physical factors
Mixed exposure
Other factors
No exposure
of smoking.The adjusted PRR's (after adjusting for
age,educationandmarital status)for subjects exposed
to dust vs. unexp osed subjects w ere: (1) male ,
management: 1.29 (0.89-1.87);(2)male, workers:1.21
(1.05-1.40);(3)female, management: 4.95 (1 .30-18.89)
and
(4)
female, workers:
3.70
(1.40-9.78).
On average,
the men
smoked
17.9
cigarettes
per day
(95%
confidence interval
[CFJ =
17.6-18.2)
and
they
had smoked
for 20.4
years
(Cl =
20.0- 20.8 ) whereas
the women smoked
9.1 (Cl =
6.6-11.6) cigarettes
per
day
for 8.1
years
(Cl =
5.8-0.4). Analysis
of
variance
showed
no
increase
in
amount smoked
per day in
dust-exposed subjects compared with
the
unexposed
subjects (data
not
shown).
byguestonNovember4,2015
http://occmed.oxfordjournals
.org/
D
ownloadedfrom
http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/ -
7/24/2019 Occup Med (Lond) 1996 Lam 351 5
5/5
T. H. Lam
et al :
Smoking and occupational hazards in China 355
DIS USSION
In the first national smoking prevalence survey in
subjects aged 15 or above in China in 1984,
65.71%
of male workers and 7.32% of female workers were
smokers (regular and occasional).
8
Male workers '
smoking prevalence was the highest among all occu-
pational groups, followed by peasants (male:
63.73%;
female: 6.63%) and governm ent functionaries or cadres
(male: 59.20%; female: 6.51%). In Guangd ong, of which
Guangzhou is the provincial capital, the prevalence
was 66.92% in male workers and 69.77% in male
cadres; the corresponding figures in females were
7.07% and 1.68 . Excluding occasional smokers
(those who smoked less than one cigarette per day),
the prevalence of regular smokers (those who smoked
one or more per day), in men for workers and cadres
was 62.68% and 64.69% respectively and the corre-
sponding figures for women were 5.87% and 1.68 .
Since 1984, although a second national survey was
condu cted in 199 1, prevalence of smoking in workers
is not yet available. It should be noted that the above
data were obtain ed by interviews in comm unity surveys
and are not comparable with our data which were
based on medical examinations by factory doctors in
the workplace. Nevertheless, these data show clearly
that smoking in workers is certainly a major public
and occupational health problem in China.
In ou r review of the literature, we did not find rep orts
on smoking in relation to various occupational expo-
sures in China. In the present study, as a descriptive
cross-sectional study, we have described the prevalence
of exposures to smoking and occupational hazards in
a reasonably representative working population in a
major city in China and we have identified the groups
most at risk. The latter should be the most important
target for preventive measures.
Smoking and exposure to occupational hazards
especially dust and chemicals are the two most
important health hazards in the working population.
In addition to the independent effects of each factor,
the two factors can have synergistic (additive or
multiplicative) effects when smoking workers are
exposed to the work hazards. One important example
is lung cancer.
9
The high prevalence of smoking in
workers exposed to dust is a major concern and the
comb ined exposu res, if not prevented, will lead to very
high incidence of lung cancer and other respiratory
disorders in the next decade. Although we did not
measure exposure to environmental tobacco smoke,
the high prevalence of smokers suggests that many
non-sm okers are exposed to passive smoking. A recent
study in China showed that passive smoking in the
workplace was associated with coronary heart
disease.
10
While the present emphasis in occupational health
in China is on prevention of exposure to occupational
hazar ds, we urge that the preven tion of smoking should
also be a top priority for health promotion in the
workplace. This is particularly relevant for the factory
doctors as they are in the best position to help their
patient workers to quit smoking. Advising patients to
quit smoking should be more straight-forward for the
doctors than to advise management to improve the
work environment because the latter is constrained by
resources and technology. It is useful for occupational
health doctors to remember that when two risk factors
interact (e.g. smoking and dust), addictively or mul-
tiplicatively, removal of one factor (e.g. smoking) will
take away the effect of that single factor and the
interaction effect of both factors (smoking plus dust)
and the health benefit will be substantial. Smoking
cessation is the most cost-effective health promotion
measure in the workplace and this is particularly the
case in China and other developing countries in which
occupational exposures are usually high and smoking
prevalence is increasing. Urgent tobacco control
measures are needed to prevent the epidemic of smoking-
and occupation-related diseases and mortality in the
workplace in China.
KNOWLEDGEMENTS
We would like to thank the Clinical Trial Service U nit,
University of Oxford for funding this study, Dr Sun
Yat Sen Foundation Fund of the Faculty of Medicine,
The University of Hong Kong for supporting Dr C. Q.
Jiang's visitorship to Hong Kong, Professor R. Peto
for advice, all the factory doctors for their participation
and Ms M. Chi for secretarial assistance.
REFEREN ES
1. Peto R, Lopez AD, Boreham J, Th un M , Heath Jr C.
Mortality
from smoking indeveloped countries1950-2000. Oxford, UK:
Oxford University Press, 1994: 101-103.
2. Yu JJ, Mattson ME, Boyd GM ,etal.A comp arison of smoking
patterns in the People's Republic of China with the United
States.
JAmMedAssoc
1990; 264: 1575-1 579.
3. Vartiainen E, Du D, Marks JS,etal.Mortality, cardiovascular
risk factors, and diet in China, Finland, and the U nited States.
Public HealthRe p 1991; 106: 41^6 .
4.
Wang W Q , Dob son AJ. Cigarette smoking and sick leave in an
industrial population in Shanghai, China.IntJ Epidemiol1992;
21: 293-297.
5.
Gong YL, Koplan
JP,
Feng W,et
al.
C igarette smoking in China,
prevalence, characteristics and attitudes in Minghang District.
JAmMedAssoc 1995; 274: 1232-1234 .
6. Jiang CQ , Lam TH , Kong C,etal.Byssinosis in Guan gzhou ,
China.OccupEnviron Med 1995; 52: 268-27 2.
7. Lee J. Odds ratio or relative risk for cross-sectional data? Int
JEpidemiol
1994; 23: 201-20 3.
8. Weng XZ, Hong ZG, Chen DY, Zhang M, Chen BZ, Tin BC.
Acollection ofdataofthe1984 national smokingsample survey.
Beijing: People's Health Publishers, 1987. (In Chinese)
9. Harrington JM, Saracci R. Occupational cancer: clinical and
epidemiological aspects. In: Raffle PAB, Adams RH, Baxter
BJ, Lee WR, eds.
Hunter's iseases of Occupations, 8th Edn.
London: Edward Arnold, 1994: 654-688.
10. He Y, Lam TH , Li LS,
et
al.Passive smoking at work as a risk
factor for coronary heart disease in Chinese women who have
never smoked.
Br MedJ
1994; 308: 380-3 84.
byguestonNovember4,2015
http://occmed.oxfordjournals
.org/
D
ownloadedfrom
http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/http://occmed.oxfordjournals.org/