Arsenic levels in fingernails as a biological indicator of exposure to arsenic.

The analysis of urine, blood, and hair has been used previously to monitor occupational exposure to arsenic (As). Although arsenic is normally present in human fingernails (usually as a result of dietary factors), this study evaluated the potential use of levels of arsenic in fingernails as a biological indicator of occupational exposure to this element. Air samples and fingernail clippings were obtained from individuals with no exposure and high, medium, and low exposure. A washing technique, previously developed to remove exogenous arsenic from hair, was modified to wash the fingernail samples collected in this study. It was demonstrated that 98% of exogenous arsenic was removed from these nails. A high correlation coefficient (r = 0.89) was observed in a comparison of the mean air arsenic concentrations of each exposure group with corresponding arsenic levels in fingernails. From the data collected, an equation was derived to estimate the air arsenic exposure level for a worker from the arsenic content of fingernails: air arsenic concentration (micrograms As/m3) = 1.79 x fingernail arsenic level (micrograms As/g nail)-5.9.

Respiratory effects of mesquite broiling.

Mesquite wood charcoal has been widely promoted for the unique taste it imparts to broiled food. We recently examined a 21-year-old mesquite broiler cook with evidence suggestive of respiratory allergy or irritation following exposure to mesquite broiler smoke in a Salt Lake City restaurant. We subsequently surveyed 13 mesquite and 17 gas-flame ("charcoal") broiler cooks to determine the prevalence of respiratory symptoms among workers exposed to broiler smoke. The survey demonstrated statistically significant (P less than or equal to .05) respiratory irritation in the mesquite broiler group compared with the gas-flame broiler group in one of four symptom categories. Two other symptom categories strongly suggested the presence of (P less than .10) respiratory irritation in the mesquite broiler group. Personal air sampling was conducted or two mesquite broiler cooks and two gas-flame broiler cooks and compared. Unidentified saturated and unsaturated aliphatic hydrocarbons (C8 through C12) with high molecular weights from 108 to 182 were present in air samples from the mesquite broiler cooks and not in the air samples from the gas-flame broiler cooks.