Chemical Toxicology Research

Dr. Zeliger’s research is in the area of toxic and carcinogenic effects of chemical mixtures on human health. His research has helped explain the cause of "mysterious" illnesses such as Gulf War Syndrome, Irradiated Mail Syndrome, neurodevelopmental disorders and some cancer clusters. Following are summaries of two of Dr. Zeliger’s published papers.


TOXIC EFFECTS OF CHEMICAL MIXTURES. Archives of Environmental Health 2003; Volume 58, No. 1, pages 23-29.

Human exposure to chemical mixtures produces three unexpected effects. The first is an enhanced acute and chronic response that results in greater than expected health effects. Toxic mixtures containing at least one lipophilic (fat soluble) and one hydrophilic (water soluble) chemical have been shown to produce effects that are as much as ten times more severe that those predicted from the known toxicities of the individual chemicals that comprise those mixtures. The second unexpected effect is low-level response. Here, the mixtures induce body reactions when exposures are to concentrations of chemicals that individually are too low to trigger symptoms. The third effect is unexpected target organ attack with clinical responses appearing in parts of the body not known to be sensitive to the individual chemicals. Each chemical mixture acts as an individual entity producing effects that often cannot be predicted.


UNEXPLAINED CANCER CLUSTERS: COMMON THREADS. Archives of Environmental Health 2004; Volume 59, No. 4, pages 172-176.

A cancer cluster is an outbreak of a particular cancer, or cancers, in a group of individuals in greater than expected numbers following a common exposure by that group to a causative agent. A number of identified cancer clusters have followed exposures to mixtures of chemicals. The causes for these cancers could not be attributed to any of the individual chemicals in the mixtures and up to now have remained unexplained. These clusters, however have three common characteristics. First, they all followed exposures to chemical mixtures than contained at least one lipophilic (fat soluble) and one hydrophilic (water soluble) component. Second, the specific combinations of lipophiles and hydrophiles act as individual entities and produce cancers not associated with exposure to any of the individual chemicals contained in the mixtures. Third, the cancers that follow these exposures can be in the form of single or multiple cancers per cluster.

This research sheds new light on the causes of childhood leukemia outbreaks in Fallon, Nevada and Woburn, Massachusetts as well as on other previously unexplained cancer clusters. Several breast cancer clusters that are being investigated also fit this model.

Dr. Zeliger is also the author of Human Toxicology of Chemical Mixtures