Blood lead and blood pressure: evidence from the Health Survey for England 1995

To examine the relationship between blood lead and blood pressure (BP) and to estimate the possible effects of a decrease in blood lead on BP.

A 2-ml blood sample was collected from a sub-sample of those included in the Health Survey for England 1995, a cross-sectional survey of a nationally representative sample of the adult English population. Blood lead concentration was measured by atomic absorption spectrometry and three BP readings were taken under standardised conditions using the Dinamap 8100 monitor. Analyses were carried out using data on 2563 men and 2763 women aged 16 and over.

In stepwise multiple regression analyses adjusting for various confounders--age, body mass index, smoking status, social class, region of residence and alcohol intake--blood lead was found to be significantly and positively associated with diastolic BP, and not systolic BP in men, but not in women. These findings were unaffected by the inclusion or exclusion of those on antihypertensive medication, by whether mean or median BP was used in the regression, or by the adjustment for alcohol consumption. A halving of currently prevalent blood lead levels is estimated to be associated with a decrease of between 0.8 to 1.1 mm Hg diastolic BP in men.

These findings in the context of other published data are consistent with a small pressor effect of environmental lead levels on BP. They support recommendations for further efforts to reduce lead in the environment.