Several techniques are employed to assess exposure to nanomaterials, each with its strengths and limitations. These techniques include:
1. Sampling and Measurement
Sampling and measurement involve collecting air, water, soil, or biological samples to determine the presence and concentration of nanomaterials. Instruments such as scanning electron microscopes (SEM), transmission electron microscopes (TEM), and atomic force microscopes (AFM) are often used.
2. Characterization
Characterization techniques determine the physical and chemical properties of nanomaterials, such as size, shape, surface area, and chemical composition. Techniques used include dynamic light scattering (DLS), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR).
3. Exposure Modeling
Exposure modeling uses mathematical models to predict the concentration and distribution of nanomaterials in various environments. Models can range from simple box models to complex computational fluid dynamics (CFD) simulations.
4. Biological Monitoring
Biological monitoring involves measuring nanomaterials in biological samples such as blood, urine, or tissues. This technique helps assess internal exposure and potential health effects. Techniques include inductively coupled plasma mass spectrometry (ICP-MS) and biomarker analysis.
5. Personal Exposure Monitoring
Personal exposure monitoring uses portable devices to measure the exposure of individuals to nanomaterials in real-time. These devices can track parameters such as particle number concentration, mass concentration, and surface area.
