Hearing loss and heavy metal toxicity in a Nicaraguan mining community: audiological results and case reports.

We measured fingernail metal levels, Békésy-type pure-tone thresholds and distortion product otoacoustic emission (DPOAE) levels in 59 subjects residing in the gold mining community of Bonanza, Nicaragua. Auditory testing revealed widespread hearing loss in the cohort. Nail metal concentrations (mercury, lead, aluminum, manganese and arsenic) far exceeded reference levels. No relationship was found between metal levels and auditory test results for the group as a whole. Statistically significant relationships were found between DPOAE response amplitudes and metal concentrations in a subgroup with less than 40 h per week of significant noise exposure; however, conclusions regarding these relationships should be tempered by the large number of analyses performed. Several young individuals with high metal levels reported neurological symptoms and had poor hearing. The data suggest that metal levels in artisanal mining communities present a significant public health problem and may affect hearing.

Survival after first esophageal variceal hemorrhage in patients with biliary atresia.

OBJECTIVE: To determine the influence of the new onset of esophageal variceal hemorrhage (EVH) on transplant-free survival in children with biliary atresia and to examine variables that predicted survival after the onset of EVH. METHODS: Retrospective chart review of 134 patients with biliary atresia who underwent portoenterostomy between 1973 and 1992 at a single institution; 29% had EVH. RESULTS: The risk of death or need for liver transplantation was 50% at 6 years after the initial episode of EVH. Patients with a serum bilirubin concentration < or =4 mg/dL at the first episode of EVH had transplant-free survival of >80% for 4 years after this episode, those with bilirubin levels >4 to 10 mg/dL had 50% survival at 1 year, and those with bilirubin levels >10 mg/dL had 50% survival at 4 months. The risk of death or transplant for a child with EVH and total serum bilirubin levels >10 mg/dL was 12.0 (95% CI: 6.0, 24.1), 4 to 10 mg/dL was 7.2 (3.1, 16.7), and < or =4 mg/dL was 0.6 (0.1, 3.1) times the risk of a same-aged child who did not have EVH. CONCLUSIONS: Children with biliary atresia and first EVH episode have a variable prognosis related to total serum bilirubin concentration at the time of the episode.