Dean Michael Klag

Open Mike: The Chemical Question

By Dean Michael J. Klag, MD, MPH ’87

We live in a sea of chemicals.

Synthetic organic chemicals make modern life possible, prevent injury and treat disease. When humans are exposed to them in ways not originally intended, however, they may have consequences that are not so beneficial. And exposure is exactly what is happening; these chemicals permeate daily life. They occupy the air we breathe, the water we drink, the food we eat, the clothes we wear and the toys our children play with.

The proof is in our blood. Exquisitely sensitive modern analytic techniques can detect more than 200 chemicals in human umbilical cord blood—evidence that mothers share more than essential nutrients with a developing fetus. Because the prevalence of childhood conditions such as asthma, food allergies and autism spectrum disorders is increasing markedly, the role of fetal exposure to a variety of chemical compounds clearly is cause for concern. Is this increase linked to chemical exposures? We do not know. Given the beneficial effects of chemicals, it’s hard to imagine living without them. However, until we know the risks of exposure, we cannot make informed decisions about their use. 

This issue of Johns Hopkins Public Health highlights work by the Bloomberg School’s Janet DiPietro and her colleagues on the effects of exposure to organochlorines—insecticides, polychlorobenzenes and other synthetic compounds—during fetal development. This pilot study, the first of its kind to measure maternal chemicals at the same time that fetal behavior is measured, suggests that organochlorines may affect fetal movement. This is crucial research, and the next step is to determine whether children’s long-term health is affected.

Much more research on the developing human fetus is necessary to fully understand the impact of chemicals on human health, individually and in mixtures. It’s an incredibly difficult area of study requiring new modes of measurement and analysis. Children and babies are also of special concern because their organ systems are still developing, which puts them at high risk.

We need to learn more about the impact on human health by chemicals, individually and in mixtures. It’s an incredibly difficult area of study.

One need only look at the sad history of lead exposure to observe the damage chemicals can inflict on young lives. Lead was once ubiquitous in our society, showing up most notoriously in gasoline and household paint. Children who ingested lead paint suffered intellectual disabilities as well as an increased risk of hypertension, cardiovascular disease and kidney disease. Generations suffered exposure before long-delayed removal of lead from paint and gasoline resulted in a dramatic fall in lead intoxication, lead poisoning and the resultant harmful effects.  Even so, far too many children still have dangerous blood lead levels.

The larger question for us today is, what other “leads” are out there? Is exposure to synthetic organic chemicals also having deleterious effects on human health and development? Which chemicals pose the greatest threats? Does the interaction of exposure to multiple chemicals magnify their effects? 

In addition to being critical public health questions, these issues have been a matter of great personal importance to me. My daughter, Sarah, was diagnosed with an autism spectrum disorder in 1995 at age 5. My late wife Wendy devoted her life to making sure that Sarah reached her maximum potential. After Wendy’s death in 2006, family and friends gave generously to a memorial fund in her memory that enabled us to support students to study developmental disabilities. We are now building on these activities to create the Wendy Klag Center for Autism and Developmental Disabilities at the Bloomberg School.

The Center, led by Mental Health chair M. Daniele Fallin with associate dean for Research Janet DiPietroas associate director, officially launches on October 15, 2013. It has a bold mission that includes identifying the etiologies of developmental disabilities like autism, devising the best possible treatment and prevention programs, and advancing policies that maximize health and minimize harm.

To accomplish this ambitious agenda, we intend to take advantage of the depth and breadth of expertise in the Johns Hopkins environment to create new synergies that will more effectively address the issue of developmental disabilities. We will bring together epidemiologists to assess and track prevalence of conditions in populations, geneticists to identify candidate genes, laboratory scientists to measure chemicals and other prenatal exposures, developmental psychologists to assess cognitive and other impairments, biostatisticians to develop new methods of detecting important signals in huge amounts of data from brain imaging tests and genomic analysis, experts to devise optimal policies to care for and support individuals with developmental disabilities, and clinicians at the cutting edge of screening and care to develop new strategies for early detection—all working on a common problem.

By bringing the best and brightest together, the Wendy Klag Center will catalyze research that has a purpose: to identify what may be harming our children and to protect the next generation.