The stature and weight of the participants were measured by Martin’s Anthropometer and weighing machine, respectively. Assessment of respiratory systems was done using a questionnaires, consisting of three parts, (i) personal and work characteristics and medical history, (ii) respiratory health and illnesses, (iii) smoking habits. Measurement of PEFR was done with the help of a Wright’s Mini Peak Flow Meter (Clement Clarke). The PEFR test was performed in standing position while holding the peak flow meter horizontally. Subjects were asked to take in a deep breath as far as possible and then blow out as hard and as quickly as possible. The highest of the three ratings was recorded. One-way ANOVA was employed for comparing the PEFR data between the three groups. Statistical analysis was performed using the statistical package (Primer of Biostatistics).

The agricultural and constructional workers were noted to work seven days a week, working 10.5 (± 1.37) and 7.2 (±1.46) hours per day, respectively. The controls worked 4.1 (±1.52) hours per day. No history of smoking or pre-existing respiratory symptoms was elicited in any child.

The average PEFR value of male agricultural workers construction workers and controls were 286.9 (±32.32) L/min, 282.5 (± 29.66) L/min and 303.0 (±31.05) L/min, respectively. There was a significant difference in PEFR values (P=0.003) between the three groups of male subjects. The average PEFR value of female agricultural workers construction workers and female control group were 272.5 (±22.0) L/min, 270.5 (± 28.38) L/min and 283.0 (±27.27) L/ min, respectively. There was a significant difference in PEFR values (P=0.039) between the three groups of female subjects. The PEFR in all groups were significantly positively correlated with age, height and weight.

The PEFR is an accepted index of pulmonary function and is widely used in respiratory medicine [1]. Similar to previous reports, we also found that the PEFR values significantly correlated with age, weight, and height of the subjects [2]. This study revealed that child construction workers had much lower PEFR value than those working in agricultural sector. Similar findings have been reported by previous workers with respect to workers in the construction industry [3,4]. Construction workers are exposed to a wide range of substances that are potentially hazardous to the respiratory system, including cement dust, wood dust from sawing, dust from the ground, fumes from welding, which lower the PEFR value [5,6]. Debray, et al. [7] suggested that the inhalation of these dust particles leads to deposition on the lining of the alveoli, which may reduce the ventilation-perfusion ratio and thus reduces the maximum oxygen uptake. This deposition may also be the cause of lower lung capacity and thus lower PEFR.

Funding: None. Competing interests: None stated.

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