TABLE 3.
Strengths and weaknesses of intratracheal instillation and versatile aerosol concentration enrichment system (VACES) on PM2.5 exposure to experimental rodents.
| Method | Intratracheal instillation | Versatile aerosol concentration enrichment system (VACES) | |
| Oral-inhalation exposure system | Whole-body exposure system | ||
| Equipment cost | Low | High | High |
| Operation difficulty | High | Low | Low |
| Animal activity level | Limited | Limited | Unlimited |
| Dosage | Instilled dosage (mg/kg of body weight or mg/animal) | Defined by the PM2.5 concentration (mg/m3) | |
| Deposition | Uneven distribution in the lung lobes | Even distribution in the lung lobes | |
| Application | Acute model, only affecting the lower respiratory tract | Acute or chronic model, affecting the whole respiratory tract | |
| Source of PM2.5 | PM2.5 powder is usually obtained through high volume air sampler collection, ultrasonic elution and vacuum freeze drying. Different elution methods have an impact on the composition of PM2.5 obtained | PM2.5 is collected directly from the air and concentrated for the required exposure concentration. The composition of PM2.5 will be affected by the spatial and temporal distribution of the collection sites | |