Dissolution of Inorganic Lead (Pb) in Synthetic Sweat: Implications for Dermal Exposure and Occupational Risk.

Area of Science:

• Environmental Science
• Toxicology
• Public Health

Background:

• Inorganic lead (Pb) is a toxicant with widespread industrial applications, posing a significant public health risk.
• Dermal exposure to lead is an under-researched route, often excluded from regulatory limits due to limited data.

Purpose of the Study:

• To investigate how synthetic sweat affects the bioaccessibility of inorganic lead for dermal absorption.
• To quantify the dissolution kinetics of inorganic lead in synthetic sweat versus deionized water.

Main Methods:

• Dissolution testing of inorganic lead nitrate in synthetic sweat and deionized water (DIW).
• Analysis of dissolution kinetics and ion concentration over a 3-hour period.
• Statistical comparison using the Wilcoxon rank-sum test.

Main Results:

• Inorganic lead dissolution was significantly lower in sweat (67% of initial mass) compared to DIW (100%).
• Precipitation of lead was observed in sweat, but not in DIW, indicating altered solubility.
• Higher variability in dissolution was noted in sweat (SD: 1.47-8.2) than in DIW (SD: 0.80-3.88).

Conclusions:

• Sweat composition inhibits the dissolution of soluble inorganic lead.
• This inhibition influences the dermal bioaccessibility of lead, suggesting sweat plays a protective role against dermal absorption.
• Further research is needed to incorporate dermal absorption influenced by sweat into regulatory exposure limits.