AC electric fields and particle deposition on a sphere.

Area of Science:

• Environmental Science
• Health Physics
• Aerosol Science

Background:

• National Radiological Protection Board identified uncertainties in particle deposition near power lines.
• Further research is needed on particle size and airflow dependence for health risk assessment.
• Previous models neglected skin temperature and texture effects on particle deposition.

Purpose of the Study:

• To investigate thermophoresis effects on particle deposition on a human head model.
• To assess the impact of electric fields on particle deposition considering thermal effects.
• To propose improved methods for presenting particle deposition data.

Main Methods:

• Empirical heat transfer data used to model thermophoretic deposition.
• Particle deposition on a sphere simulating the human head analyzed.
• Comparison of deposition models with and without electric field and thermal effects.

Main Results:

• Thermophoresis significantly impacts particle deposition for diameters >6 nm.
• Skin temperature is crucial for modeling deposition of larger particles.
• Electric fields enhance deposition, but models neglecting thermal effects are inaccurate for skin.

Conclusions:

• Accurate modeling of particle deposition requires considering thermophoresis and skin temperature.
• Existing models may overestimate or underestimate health risks due to simplifications.
• Collection efficiencies are a more reliable metric than deposition ratios for assessing exposure.