Am. J. Respir. Crit. Care Med., Vol 153, No. 5, May 1996, 1553-1559.
Respiratory health of California rice farmers
SA McCurdy, TJ Ferguson, DF Goldsmith, JE Parker and MB Schenker
Division of Occupational@Environmental Medicine and Epidemiology, University of California, Davis 95616-8638, USA.
Rice farmers are occupationally exposed to agents that may affect
respiratory health, including inorganic dusts and smoke from burning of
agricultural waste. To assess respiratory health of this occupational
group, we conducted a cross-sectional study, including a self- administered
health and work questionnaire, spirometry, and chest radiography among 464
male California rice farmers. Mean age +/- SD was 48.3 +/- 15.2 yr; mean
duration of rice farming was 25.7 +/- 14.3 yr. Prevalences for respiratory
symptoms were: chronic bronchitis (6.3%), physician-diagnosed asthma
(7.1%), and persistent wheeze (8.8%). Chronic cough was reported by 7.1% of
respondents and was associated with reported hours per year burning rice
stubble. Mean FEV1 and FVC were at expected values. FEV1 was inversely
associated with years working in rice storage and use of heated rice
dryers. Mean FEF25-75 was 93% of expected and was inversely associated with
rice storage activities involving unheated rice driers. ILO profusion
scores > or = 1/0 for small irregular opacities were seen in 18 (10.1%)
of 178 chest radiographs. Study findings suggest increased asthma
prevalence among California rice farmers. Radiologic findings consistent
with dust or fiber exposure were increased compared with those of the
general population, although no associations with specific farming
activities were identified.
