Page 43 - HA Convention 2016 [Abstracts (Day 1)]

Masterclasses HOSPITAL AUTHORITY CONVENTION 2016

M8.3 Lead in Drinking Water Incident in Hong Kong 2015 16:15 Room 221

Lead Exposure during Pregnancy
Leung WC
Department of Obstetrics and Gynaecology, Kwong Wah Hospital, Hong Kong

In 2015, the findings of elevated lead (Pb) level in tap water in various public housing estates in Hong Kong has resulted in
significant public concerns and anxiety. The extent of which is disproportional to the actual health risks. Let’s look into the
problem from a scientific point of view with evidence-based medicine. Apart from the World Health Organization and Centers
for Disease Control and Prevention guidelines, the Avon Longitudinal Study of Parents and Children (ALSPAC) which is the
largest prospective birth cohort study regarding the adverse effects of maternal Pb levels on birth outcomes, is most relevant.
Pregnant women (fetal:maternal Pb ratio = 0.8) and usually not lactating women (neonatal:maternal ratio = 0.03 only) are at
higher risk from Pb exposure because of related adverse pregnancy outcomes such as preterm delivery, pre-eclampsia, low
birth weight, lower head circumference and crown heel length at birth, as well as abnormal childhood cognitive development
and behaviour. Note that there are always confounding factors including socioeconomics, smoking, alcohol, caffeine, calcium
intake and others. But most important is the actual blood Pb level detected in the pregnant woman during her antenatal
course and puerperium, as well as the cord blood Pb level at delivery. The level of concern is 5 ug/dl, below which any
adverse effect is minimal. Under the voluntary blood Pb level screen programme for the affected public housing estates
starting in July 2015, there were only 4 pregnant women found to have elevated blood Pb levels > 5 ug/dl. Their longitudinal
clinical profile will be presented, illustrating a number of interesting phenomena.

Tuesday, 3 May

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