Prolonged exposure to arsenic in UK private water supplies: toenail, hair and drinking water concentrations.

Chronic exposure to arsenic (As) in drinking water is an established cause of cancer and other adverse health effects. Arsenic concentrations >10 µg L(-1) were previously measured in 5% of private water supplies (PWS) in Cornwall, UK. The present study investigated prolongued exposure to As by measuring biomarkers in hair and toenail samples from 212 volunteers and repeated measurements of As in drinking water from 127 households served by PWS. Strong positive Pearson correlations (rp = 0.95) indicated stability of water As concentrations over the time period investigated (up to 31 months). Drinking water As concentrations were positively correlated with toenail (rp = 0.53) and hair (rp = 0.38) As concentrations - indicative of prolonged exposure. Analysis of washing procedure solutions provided strong evidence of the effective removal of exogenous As from toenail samples. Significantly higher As concentrations were measured in hair samples from males and smokers and As concentrations in toenails were negatively associated with age. A positive association between seafood consumption and toenail As and a negative association between home-grown vegetable consumption and hair As was observed for volunteers exposed to <1 As µg L(-1) in drinking water. These findings have important implications regarding the interpretation of toenail and hair biomarkers. Substantial variation in biomarker As concentrations remained unaccounted for, with soil and dust exposure as possible explanations.

What are the costs and benefits of patient notification exercises following poor infection control practices in dentistry?

BACKGROUND: Allegations of serious failures in infection control practice were made against a dentist practicing in the South West of England. The dentist (who tested negative for Blood Borne Viruses (BBVs)) was immediately suspended. METHODS: Because inadequate infection control presents a potential risk of transmitting BBVs between patients, a notification exercise was undertaken. Of 7625 patients contacted, 2780 (37%) were tested. RESULTS: Nine cases of Hepatitis B (HBV) and four cases of Hepatitis C (HCV) were identified, of which seven were previously diagnosed. None of these were children. All of the six newly diagnosed cases had recognized risk factors for BBVs. The costs of the notification exercise were estimated at £311,500 of which £165,000 was staff costs, (£51,916 per newly diagnosed case). CONCLUSION: This study did not demonstrate any patient-to-patient transmission of blood-borne viruses but the response rate was relatively low. There are significant costs associated with undertaking notification exercises. These findings should inform future recommendations and practice in this area.