Center for Environmental Health Sciences (CEHS)
The mission of the MIT Center for Environmental Health Sciences (CEHS) is to take a leadership role in facilitating and promoting research into biological effects of exposure to environmental agents in order to understand and predict how such exposures affect human health. Three fundamental components influence the health effects of environmental exposures: the nature of the exposure itself, the duration of the exposure, and how well the exposed organism is equipped to deal with the exposure. In other words, the organism's genetically programmed susceptibility. These are the broad-brush strokes of what Environmental Health Sciences research is all about.
Students interested in participating in our program should contact the faculty members directly. Although a formal proposal does not need to be submitted until a project has been designed with a faculty member, students seeking to work with a CEHS faculty member should have an aim in mind and be able to discuss and explain how working in this field would enrich not only the student's educational goals, but also those of the research environment.
All individuals working in the laboratory environment are required to read the applicable Safety and Chemical Hygiene Plan. Additionally, they may also be required to complete a program in Radiation Protection. The CEHS safety representative, Dr. Koli Taghizadeh, will arrange specific safety training according to the laboratory program specifics.
The CEHS has five major research themes: (i) DNA Damage, DNA Repair and Mutagenesis; (ii) Inflammation Chemistry and Biology; (iii) Microbes and Disease Susceptibility; (iv) Bioengineering for Toxicology; and (v) Exposure and Response.
DNA Damage, DNA Repair and Mutagenesis
The CEHS has had a very long history studying the chemistry of environmental DNA damaging agents, the DNA damages they induce, the discovery of DNA repair pathways, elucidation of mutagenic and cytotoxic mechanisms and how these contribute to the induction of cancer and other diseases. A classic exemplar of such CEHS research was the identification of the chemical Aflatoxin B1 as the mutagenic toxin produced by Aspergillus flavus growing on peanuts, identification of the Aflatoxin B1-induced DNA adduct at the N7 position of guanine, demonstration that it leads to G:C to T:A mutations in p53 and other genes elevating risk of liver cancer in Asian, African and other populations consuming contaminated cereal grains. Collectively this research reached from the Angstrom level of chemical and molecular structures to the global level of human populations.
Inflammation Chemistry and Biology
It has been estimated that a large fraction of the global cancer burden occurs in individuals suffering chronic inflammatory responses, and chronic inflammation has become accepted as an important contributor to the etiology of many different tumor types. An estimated 18% of the global cancer burden can be attributed to infectious agents, most of which activate the innate immune response in the host. ;Hepatitis B and C viruses that predispose to liver cancer and Helicobacter pylori that predisposes to gastric cancer, each elicit chronic inflammation and together these agents account for 10% of the global cancer burden. These numbers underestimate the fraction of cancers with inflammation as a component in their etiology, as inflammation-related cancer is not always linked to infectious agents. Idiopathic inflammatory bowel diseases like ulcerative colitis (UC) and Crohn’s disease predispose to colorectal cancer; asbestos related respiratory inflammation sensitizes to mesotheliomas and bronchiomas; and chronic acid reflux disease leads to Barrett’s esophagus, a metaplastic disorder associated with chronic inflammation and an enormous predisposition to esophageal cancer. Factors associated with inflammation can be linked to every stage of cancer development, and in recent years the CEHS has made many contributions to dissecting the role that the release of reactive oxygen and nitrogen species (RONS) by macrophages and neutrophils play in cancer etiology.
Microbes and Disease Susceptibility
Advances over the past decade have mandated a broader view of environment-health linkages, in which genomics and ecology play an increasingly prominent and important role. Future advances require better understanding of evolution, gene flow, and ecosystem processes. Gene flow, for example, can affect the distribution of pathogenicity, or the acquisition of antibiotic resistance or biodegradative capability in microbial communities. Ecosystem processes govern the nature of coexisting populations at scales from that of the gut flora to that of continents, with direct effects on humans at all scales. Examples of projects ongoing as part of this research theme include: population dynamics of pathogenic and non-pathogenic Vibrio species in natural waters, the ecology of the lower gut and how that influences cancer susceptibility, and the ecology and evolution of microorganisms in nature.
Bioengineering for Toxicology
The studies in this research theme are aimed at developing new experimental tools and analytical methods spanning the molecular level to the systems level, for exploring biological responses to environmental exposures. The experimental tools include the following: construction of tissue engineered physiological microreactors that bridge the gap between cell culture, animal models, and humans; developing genomic and proteomic approaches for systematic measurements; applying state-of-the-art mechanical engineering to devise new ways of monitoring biological events and single molecule biochemical events; development of multi-photon imaging methods that allow in situ quantification of events such as single cell apoptosis and DNA recombination; use of mathematical modeling at the systems biology level of cellular events such as apoptosis; and the invention of analytical methods using statistical (Bayesian) and deterministic models of signal transduction networks and computational models of protein interactions in the context of different cell compartments. Given the nature of these studies, major progress has so far been made at the molecular, pathways and networks, and cellular and tissue levels.
Exposure and Response
This research theme is deliberately broad to capture the many science and engineering research projects that do not neatly fit into the other four research themes, but which are important to the Center because they do perfectly fit into our overall mission, namely to study the biological effects of, and processes of exposure to, chemical, physical and biological environmental agents with the goals of understanding and predicting how such exposures affect human health.
CEHS MEMBERS:
The links on faculty names below, will bring you to their web sites, which describe their research interests and provide contact information.
Prof. Jiali Han - Harvard
Prof. David Hunter - Harvard
Prof. Ravi Thadhani - Harvard
