Potential hazards of toxic metals found in toothpastes commonly used in Nigeria.
BACKGROUND
Toothpastes have multi-functional configurations as oral care products. They can however constitute a pos- sible source, amongst others, of toxic metal exposure in public health. Indeed, the public health impact of personal hygiene and consumer products is largely unknown.


OBJECTIVE
To determine the level of toxic metals (lead, cadmium, cobalt, chromium, nickel) in toothpastes available in Nigeria, (home produced and imported), and assess the potential risk to the people.


METHODS
The samples of toothpastes commonly used in Nigeria were tested. Using a market basket protocol thirty five different brands of toothpaste were used. Samples were digest by addition of 10 mL mixture of conc. nitric and hydrochloric acids (HCl:HNO(3), 3:1), followed by heating to dryness. 20 mL deionized water was added, stirred and filtered. The filtrate was made up in standard volumetric flask and lead, cadmium, chromium, cobalt and nickel concentrations were determined using the atomic absorption spectrophotometry 205A. The daily intake of metals and target hazard quotient (THQ) were then calculated.


RESULTS
Pepsodent and Flodent had the highest levels of lead at respectively 23.575 and 18.092 mg/kg while Colgate Herbal had the highest nickel of 18.535 mg/kg. The daily intake estimates of all imported toothpaste samples were below the stated upper limits (UL). All target hazard quotients were also found to be below one.


CONCLUSIONS
Although the UL, THQ and daily intake rates were all normal, the high levels of lead in some of the tooth- pastes an important concern to public health suggesting that pre-marketing safety studies of toothpastes may be worthwhile for the regulatory authorities.
Toxicology Unit, Faculty of Pharmacy, University of Port Harcourt, Port Harcourt, Rivers State, Nigeria.
Orish Ebere
OE
Orisakwe
Faculty of Pharmacy, Madonna University Elele, Port Harcourt, Rivers State, Nigeria.
Kenneth Obinna
KO
Okolo
Faculty of Pharmacy, Madonna University Elele, Port Harcourt, Rivers State, Nigeria.
Zelinjo Nkeiruka
ZN
Igweze
Department of Medical Laboratory Science, Faculty of Science, Rivers State University of Science and Technology Port Harcourt, Port Harcourt, Rivers State, Nigeria.
Godwin Chukwuebuka
GC
Ajaezi
Toxicology Unit, Faculty of Pharmacy, University of Port Harcourt, Port Harcourt, Rivers State, Nigeria.
Nnaemeka Arinze
NA
Udowelle
D062067:Chemical Safety; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data*; D006801:Humans; D019216:Metals, Heavy / Q000032:analysis*; D009549:Nigeria; D011356:Product Labeling / Q000706:statistics & numerical data*; D018570:Risk Assessment; D013054:Spectrophotometry, Atomic; D014099:Toothbrushing; D014100:Toothpastes / Q000737:chemistry* / Q000592:standards
D019216:Metals, Heavy; D014100:Toothpastes