. 2015 Jun 30;187(7):475. doi: 10.1007/s10661-015-4689-x

Table 4.

Concentration of heavy metals (copper (Cu), zinc (Zn), iron (Fe), cadmium (Cd), lead (Pb) and chromium (Cr)) in water in the four sampling systems along the Nakivubo channel in Kampala (sampling period: 18 and 19 November 2013).

Sampling system	Concentration in mg/L
Heavy metals	Min	Max	Mean	Lower 95 % CI	Upper 95 % CI	Guideline values
Nakivubo channel (n = 5)
Cu	0.90	6.30	3.30^a	1.60^a	5.00^a	1.00
Zn	0.20	3.00	1.40	0.70	2.00	5.00
Fe	8.10	38.10^a	21.50^a	13.90^a	29.00^a	10.00
Cd	0.05	0.31^a	0.14^a	0.07^a	0.22^a	0.10
Pb	0.09	3.00^a	1.60^a	0.94^a	2.26^a	0.10
Cr	0.01	0.01	0.06	0.03	0.08	1.00
Nakivubo wetland (n = 12)
Cu	0.90	4.00^a	2.30^a	1.70^a	3.00^a	1.00
Zn	0.01	1.10	0.30	0.10	0.60	5.00
Fe	10.90^a	33.50^a	18.60^a	14.10^a	23.10^a	10.00
Cd	0.01	0.31^a	0.13^a	0.07	0.19^a	0.10
Pb	0.10	2.60^a	1.02^a	0.56^a	1.49^a	0.10
Cr	0.003	0.21	0.06	0.01	0.10	1.00
Community areas (n = 2)
Cu	1.70^a	4.20^a	3.00^a	–	–	1.00
Zn	0.17	0.20	0.19	–	–	5.00
Fe	18.20^a	27.60^a	22.90^a	–	–	10.00
Cd	0.14^a	0.26^a	0.20^a	–	–	0.10
Pb	1.30^a	3.80^a	2.50^a	–	–	0.10
Cr	0.01	0.02	0.02	–	–	1.00
Lake Victoria (n = 4)
Cu	1.00	2.10^a	1.40^a	0.60^a	2.20^a	1.00
Zn	0.20	0.50	0.30	0.10	0.50	5.00
Fe	15.00^a	21.10^a	17.70^a	12.70^a	22.70^a	10.00
Cd	0.09	0.11^a	0.10	0.09^a	0.11^a	0.10
Pb	0.91^a	1.64^a	1.25^a	0.76^a	1.73^a	0.10
Cr	0.01	0.02	0.014	0.004	0.023	1.00

Geometric means and 95 % confidence intervals (CIs) are indicated

^aConcentrations exceeding maximum acceptable concentrations (MACs) as per Ugandan guidelines (NEMA 1999)