IADR Abstract Archives
Fingernails and Toenails Good Biomarkers of Chronic/Sub-chronic Fluoride Exposure
Objectives: This study aimed to investigate the relationship between fluoride concentration in fingernails (FFN) and toenails (FTN) (µg/g) and i) total daily fluoride intake (TDFI), ii) drinking water fluoride concentration (FW).
Methods: Sixty healthy children (4-5y) and their parents (≥20y) in low- and high fluoride water areas (LFA, HFA, respectively), in Nigeria, participated. Total daily dietary fluoride intake (TDDFI) was assessed by food frequency questionnaire coupled with analysis of fluoride content of food and drinks consumed. Toothpaste ingestion was assessed through questionnaires. TDFI was calculated from TDDFI and toothpaste ingestion. Fingernail and toenail clippings were cleaned in a sonicator with double-distilled ionized water and oven dried. Fluoride concentrations of diet and nail clippings were measured by fluoride-ISE after overnight HMDS-facilitated diffusion.
Results: TDFI [mean(SD)] for children and adults respectively was 0.075(0.036) and 0.036(0.020) mg/kgbw/d in LFA (FW=0.04 mg/L) and 0.277(0.184) and 0.125(0.093) mg/kgbw/d in HFA (FW=3.05 mg/L). Mean(SD) FFN was 3.23(2.63) and 2.80(1.77) µg/g in children and adults respectively in LFA and 12.58(7.05) and 9.41(3.74) µg/g respectively in HFA, whereas mean(SD) FTN was 4.07(3.72) and 3.28(2.82) µg/g in children and adults respectively in LFA and 11.38(5.23) and 10.20(5.79) µg/g respectively in HFA. Moderate, positive and statistically significant correlations were found between FFN and TDFI in children (Pearson’s correlation (PC) = 0.448, p=0.002) and in adults (PC=0.506, p<0.001). Positive and statistically significant correlations were found between FTN and TDFI in children (PC=0.488, p<.001) and in adults (PC=0.502, p<0.001). FFN and FTN showed strong positive and statistically significant correlations with FW for both children and adults.
Conclusions: Fingernail and toenail clippings may be used as a biomarker of chronic fluoride exposure due to the good relationship established with TDFI.
Methods: Sixty healthy children (4-5y) and their parents (≥20y) in low- and high fluoride water areas (LFA, HFA, respectively), in Nigeria, participated. Total daily dietary fluoride intake (TDDFI) was assessed by food frequency questionnaire coupled with analysis of fluoride content of food and drinks consumed. Toothpaste ingestion was assessed through questionnaires. TDFI was calculated from TDDFI and toothpaste ingestion. Fingernail and toenail clippings were cleaned in a sonicator with double-distilled ionized water and oven dried. Fluoride concentrations of diet and nail clippings were measured by fluoride-ISE after overnight HMDS-facilitated diffusion.
Results: TDFI [mean(SD)] for children and adults respectively was 0.075(0.036) and 0.036(0.020) mg/kgbw/d in LFA (FW=0.04 mg/L) and 0.277(0.184) and 0.125(0.093) mg/kgbw/d in HFA (FW=3.05 mg/L). Mean(SD) FFN was 3.23(2.63) and 2.80(1.77) µg/g in children and adults respectively in LFA and 12.58(7.05) and 9.41(3.74) µg/g respectively in HFA, whereas mean(SD) FTN was 4.07(3.72) and 3.28(2.82) µg/g in children and adults respectively in LFA and 11.38(5.23) and 10.20(5.79) µg/g respectively in HFA. Moderate, positive and statistically significant correlations were found between FFN and TDFI in children (Pearson’s correlation (PC) = 0.448, p=0.002) and in adults (PC=0.506, p<0.001). Positive and statistically significant correlations were found between FTN and TDFI in children (PC=0.488, p<.001) and in adults (PC=0.502, p<0.001). FFN and FTN showed strong positive and statistically significant correlations with FW for both children and adults.
Conclusions: Fingernail and toenail clippings may be used as a biomarker of chronic fluoride exposure due to the good relationship established with TDFI.