Excessive lead absorption resulting from exposure to lead naphthenate

Area of Science:

• Occupational Health
• Environmental Toxicology
• Industrial Hygiene

Background:

• No prior studies investigated the link between lead naphthenate exposure and human lead absorption.
• Lead naphthenate is used in industrial applications, posing potential exposure risks.

Purpose of the Study:

• To investigate the relationship between occupational exposure to lead naphthenate and lead absorption in humans.
• To quantify lead levels in air and biological samples of exposed workers.

Main Methods:

• A cross-sectional study was conducted in an aluminum forging facility using lead naphthenate without local ventilation.
• Air lead concentrations were measured in the work environment.
• Blood lead (PbB) and zinc protoporphyrin (ZPP) levels were measured in exposed forge operators and unexposed control workers.

Main Results:

• Mean air lead concentration in the forging area was 96 µg/m³ (range: 12-430 µg/m³).
• Exposed forge operators (n=29) had a significantly higher mean blood lead concentration (63 µg/dl) compared to unexposed workers (17 µg/dl; P < .001).
• Mean zinc protoporphyrin levels were also significantly elevated in exposed workers (265 µg/dl) versus controls (26 µg/dl; P < .001).
• Nineteen exposed workers had blood lead levels exceeding 60 µg/dl, with a maximum of 108 µg/dl.

Conclusions:

• This study provides the first evidence associating lead naphthenate use with increased lead absorption in humans.
• Occupational exposure to lead naphthenate in the described industrial setting poses a significant risk for lead poisoning.
• The findings underscore the need for implementing effective ventilation and safety measures in workplaces using lead naphthenate.