We are exposed to the environment. All. The. Time. Through the air we breathe, the food we eat, the home we live in. Normally, exposure to the environment is not a problem. We have evolved in the environment and adapted to the environment.

However, since the industrial revolution and driven by the ever growing need to optimize productivity, countless compounds have been developed and implemented in almost every aspect of human life, including consumables like water bottles and food wrapping, personal care products, as well as fruits and vegetables treated with agricultural chemicals. Many of those have subsequently been identified as environmental toxicants with devastating health effects for the exposed population. 

Just imagine: Socioeconomic costs associated with exposure to environmental toxicants are estimated to exceed 10% of the global gross domestic product [1]! 

Although restrictions and regulations aim to minimize exposure, their implementation however, often occurs with great delay and regulatory measures can vary significantly between countries, meanwhile rendering exposure to environmental toxicants a constant and significant threat to long term public health. Importantly, accumulating evidence suggests that exposure to environmental toxicants not only inflicts adverse health effects in the exposed individual but can persist in subsequent unexposed generations through abnormal epigenetic modifications in sperm and egg [2, 3]. Most prominently, the dramatic deterioration in human sperm quality over the past 50 years has been associated with environmental exposure to commonly used toxicants [4].

Despite progress in our general understanding of inheritable epigenetic modifications as a result of environmental exposure, their effects on immunity and host defense and consequent impact on multiple pathologies including cancer, microbial susceptibility, and autoimmune diseases across generations is severely understudied.

Is it possible, that the rapid increase in immune-mediated diseases (think type 1 diabetes, asthma, allergies, eczema…) are a result of the environment our parents and grandparents lived in? 

And maybe even more important: Is it possible, that the environment we are living in today might cause immune pathologies in our children and grandchildren?

These are the questions that are driving our research. Our mission in the Liedmann lab is to discover how exposure to environmental toxicants changes the immune system for generations, use this information to explain and treat immune disorders induced by ancient exposure, and thereby do our part in the global effort toward life in a toxic-free environment. As this is a mammoth task, we recognize that the broadest impact the lab can possibly have is through the people we train and their contribution to science in the future.

[1] Grandjean, P. and M. Bellanger, Calculation of the disease burden associated with environmental chemical exposures: application of toxicological information in health economic estimation. Environ Health, 2017. 16(1): p. 123.

[2]  Perez, M.F. and B. Lehner, Intergenerational and transgenerational epigenetic inheritance in animals. Nat Cell Biol, 2019. 21(2): p. 143-151.

[3] Skinner, M.K., Environmental epigenetic transgenerational inheritance and somatic epigenetic mitotic stability. Epigenetics, 2011. 6(7): p. 838-42.

[4] Levine, H., et al., Temporal trends in sperm count: a systematic review and meta-regression analysis. Hum Reprod Update, 2017. 23(6): p. 646-659.