Blood lead level and blood pressure of bus drivers in Bangkok, Thailand

This study aims to evaluate blood lead level (PbB) and blood pressure of bus drivers in Bangkok, Thailand, after the phasing out of lead in gasoline. The subjects comprised of 439 male bus drivers whose age ranged between 23 and 59 yr with the mean age of 42 +/- 8 yr. Average working experiencewas 10 +/- 7 yr. The mean of the systolic and diastolic blood pressure were 131 +/- 17 and 81 +/- 11 mmHg, respectively. PbB ranged from 2.5 to 16.2 mu g/dl with the mean PbB of 6.3 mu g/dl. Prevalence rate of systolic and diastolic hypertension among bus drivers were 23.0% and 18.2%, respectively. There were significant correlations between PbB and blood pressure both in systolic and diastolic blood pressure after controlling for age, BMI, alcohol consumption, smoking and physical exercise. However, the data on psycho-social factors which may affect on blood pressure of bus drivers were not available. Therefore, further study is needed to clarify the relationship between blood pressure and psycho-social stress among bus drivers in Bangkok. These findings suggested lead exposure at low PbB is related to increases in blood pressure.