Dietary Content and Potential Health Risks of Metals in Commercial Black Tea in Kampala (Uganda)

Abstract

Tea (Camellia sinensis (L.) Kuntze) is among the most widely consumed non-alcoholic beverages. It is a rich source of essential dietary elements mainly potassium and manganese. Tea may also contain toxic metals such as cadmium and lead which pose a threat to human health because of their toxicity. Twenty samples of commercial black tea in Kampala city were randomly obtained and analysed for potassium, sodium, aluminium, arsenic, cadmium, chromium, copper, iron, mercury, manganese, nickel, lead and zinc using Atomic Absorption Spectrophotometry. Human health risks due to exposure to toxic elements from daily consumption of tea were determined using incremental lifetime cancer risk and non-cancer hazard quotient. Metal contents of black tea sold in Kampala were below international regulatory limits. The estimated daily intake of the elements in two grams of black tea was below the recommended values. Hazard quotient and hazard index were within acceptable range. Total cancer risk levels for all the teas were also within United States Environmental Protection Agency (USEPA) acceptable range. Daily consumption of one cup containing two grams of black tea over a lifetime will promote consumer overall health and wellbeing.

Mercuric pollution of surface water, superficial sediments, Nile tilapia (Oreochromis nilotica Linnaeus 1758 [Cichlidae]) and yams (Dioscorea alata) in auriferous areas of Namukombe stream, Syanyonja, Busia, Uganda

“…where E f = exposure frequency (365 days/year), E d = exposure duration, the average lifetime (58.65 years for an adult Ugandan) (Bamuwamye et al, 2017), F ir is the fresh food ingestion rate (g/person/day) = 48 for fish and 301.0 and 231.5 for yams eaten by adults and children respectively) (Wang et al., 2005; Ge, 1992), C f is the conversion factor (0.208) for fresh weight ( F w ) to dry weight ( D w ) for fish and 0.085 for yams (considering it as a vegetable) (Adedokun et al, 2016), C hm = heavy metal concentration in the foodstuffs (µgg −1 F w), W ab = average body weight (considered to be 15 kg for children (Ordonez et al, 2011) and 60 kg for adults (Ali & Hau, 2001)), T aet = average exposure time for non-carcinogens (given by the product of E d and E f ) (Saha & Zaman, 2012), S A is the exposed surface area in c m 2 = 4,350 for adults and 2,800 for children (Ordonez et al, 2011), AF is the skin adherence factor in mg/cm 2 /day = 0.7 for adults (Wojciechowska et al, 2019) and 0.2 for children (Ordonez et al, 2011).…”

Physicochemical Quality and Health Risks Associated with Use of Water from Nyamwamba River, Kasese, Western Uganda

“…Where in C m = heavy metal concentration (mg/L), W ir is the water ingestion rate = 1.8 L/day and 21.0 L/day for children and adults, S A is the exposed surface area = 2,800 cm 2 for children and 24,350 cm 2 for adults [34], DAF is the dermal absorption factor = 0.01 for carcinogenic HMs and 0.001 for non-carcinogenic HMs [35], AF is the skin adherence factor in mg/cm 2 /day = 0.2 and 0.7 for children and adults [36], E f = exposure frequency (365 days/year), E d = exposure duration, the average lifetime (58.65 years for an adult Ugandan) [16,37], W ab = average body weight (considered to be 15 kg for children and 60 kg for adults), T aet is the average exposure time for non-carcinogens = E f × E d [38].…”

Heavy Metal Accumulation in Vegetables Grown in Rock Soils of Kilembe Copper Mine, Kasese, Western Uganda

“…Where E F = exposure frequency (365 days/year), E D = exposure duration, the average lifetime (58.65 years for an adult Ugandan) [15,16], Cv = heavy metal concentration in the vegetable sample (mg/kg), F ir is the fresh food ingestion rate (kg/person/day) = 0.09 for tomatoes and 0.085 for cabbages (considering it as a vegetable) [17], W ab = average body weight (considered to be 15 kg and 60 kg for children and adults, respectively), T aet is the average exposure time for non-carcinogens = E f × E d [18].…”