The major focus of my research laboratory has long been the effects of inhaled toxicants on immune system function and the reproductive process. Ongoing studies include those using inhaled nanoparticles, particulate matter (PM), cigarette smoke or its components, as well as alternative tobacco products such as gutkha and hookah.
Nanoparticles One of our main interests is studying the effects of inhaled metal nanoparticles (oxides of cadmium or silver and gold) on embryonic, fetal, and postnatal development and growth. Nanoparticles hold tremendous promise for improving our lives in areas such as medicine and allowing for cleaner energy production. However, many characteristics of materials change when used on the nano-scale (< 100 nm) and a better understanding for the potential toxic effects is needed to ensure safety of not only the end-users of these products, but also for those involved in their manufacture. For instance, we showed exposure to inhaled cadmium oxide nanoparticles during pregnancy lead to shortened body length of newborns and leads to diminished rate of weight gain early in life. The mechanisms for these actions are part of on-going studies in the laboratory. Other related studies have focused on how systemic exposure to silver nanoparticles, which may be released from the medical devices in which they are used as antimicrobial agents, can affect the immune system. These studies show that silver nanoparticles accumulate in the spleen, where they cause changes to splenic morphology as well as alter immune cell profiles, and have discovered that smaller-sized nanoparticles have a greater potential for harm than do larger ones. Particulate Matter Another focus in my laboratory is how particulate matter in air pollution causes premature birth and low birth weight. There have been many studies making this link in the epidemiologic literature with mixed results as the concentration levels, time(s) of greatest sensitivity to the placenta and developing baby, and which components of particulate matter pose the greatest harm are inconsistent in these models. We are trying to understand how exposure at different times during pregnancy can lead to premature birth/low birth weight as well as to determine the mechanisms involved and potential intervention strategies to improve the health of the baby. We have shown experimentally that exposure to PM can cause changes in the uterine environment that lead to premature birth and that timing and duration of exposure are both important factors. Tobacco Smoke and Alternative Tobacco Products A long time focus in my lab is gaining a better understand for how cigarette smoking during pregnancy affects the unborn offspring, and how these effects increase a child?s susceptibility to diseases such as cancer or heart disease later in life (i.e., developmental basis of adult disease). This model has recently evolved to include examining how smokeless or ?heat-not-burn? tobacco products can affect the reproductive process. These products, gutkha (South Asian product) and shisha smoked in a hookah (Middle Eastern product), are traditionally used by ethnic/immigrant populations, but are now being used with greater frequency by the population at large. These products, along with e-cigarettes are being studied for their toxic effects on male and female reproduction, immunity, and brain neurotransmitters which lead to addiction. Our data show that short-term exposures to gutkha is associated with decreased body weight, circulating testosterone, sperm quality and concentrations in exposed male mice as well as altered mRNA expression of important enzymes in the liver associated with biotransformation.
Professor, Department of Environmental Medicine
PhD from Rutgers Biomedical and Health Sciences
Reproductive toxicology. 2018 Apr 27; 79:16-20
Neurotoxicology. 2018 Mar 29; 65:196-206
Neurotoxicology. 2018 Mar 07; 65:231-240
Toxicological sciences. 2018 Mar 01; 162(1):276-286
Methods in molecular biology. 2018; 1803:169-180
Environmental health perspectives. 2017 Jul 27; 125(7):077020-077020
Toxicological sciences. 2017 Apr 1; 156(2):492-508
Journal of exposure science & environmental epidemiology. 2016 May 11; 27(2):221-226