Assessment was done of heavy-metal contamination
and its related health risks in urban vegetable farming
in Accra. Samples of irrigation water (n = 120), soil
(n = 144) and five different kinds of vegetable (n = 240)
were collected and analyzed for copper, zinc, lead, cadmium,
chromium, nickel and cobalt. All water, soil and
vegetable samples contained detectable concentrations of
each of the seven heavy metals except for irrigation water
which had no detectable chromium, cadmium and cobalt.
All heavy-metal levels were below permissible limits except
lead on vegetables which was 1.8–3.5 times higher. Health
risk assessments showed for all elements that normal consumption
of each of the vegetables assessed poses no risk.
The highest hazard index obtained was 42 % for wastewater
irrigated cabbage. Though within permissible limits, cabbage
and ayoyo had the highest potential risk. Compared
with previous studies on the same sites, the data show that
the risk from heavy metals is less significance than that from
pathogen contamination which has positive implications for
risk mitigation.