For 20 years, our School has hosted the Harvard-EPA Center on Particle Health Effects. This center focuses on the impact of atmospheric particles on the environment and human populations. We have studied particles of a wide range of sizes, including ultrafine particles, which are in the same size range as nanoparticles (< 100 nanometers). Over the past decade, we have developed an array of novel particle generation and exposure technologies for the physico-chemical and toxicological characterization of atmospheric particles. Those techniques encompass systems for personal and micro- environmental exposure assessments, as well as versatile systems for generating aerosols for exposing humans and animals to ambient or source-specific particles including ultrafine particles. These innovative aerosol methods have been adopted as reference methods by scientists and public health assessors.
We are currently focused on the development of methods and systems for the physico-chemical and toxicological characterization of engineered nanomaterials (ENMs), as well as on nano-exposure assessment studies and emerging concepts for safe formulation of nanomaterials. We have recently developed the Harvard Versatile Engineered Nanomaterial Generation System (VENGES) which is a suitable platform to generate industrially relevant metal oxides while varying composition, size, and shape. Currently, we are studying the fate and transport of these metal oxides in environmental and biological media. We have also generated an extensive ENM Reference Library which contains well-characterized ENMs suitable for nano-EHS studies. We employ an array of state-of-the-art instruments for the physico-chemical and morphological characterization of ENMs, both in powder form and in various media (air, physiologic fluids, water, etc.). Instruments include scanning mobility particle sizer (SMPS), direct light scattering (DLS) systems, scanning electron microscopes, N2 adsorption and ICP-MS. Supporting technologies for the physico-chemical and morphological characterization of nanomaterials are also available at the Harvard Center for Nanoscale Systems at Harvard School of Engineering and Applied Science (SEAS).