Dioxins are by-products of industrial processes that are commonly regarded as highly toxic and are environmental pollutants. Their toxicity levels range greatly due to the broad class definition, but they are considered to play major roles in reproductive and developmental problems in humans. They interfere with hormones and have been known to cause cancer as well. Most intakes of dioxin-like chemicals are from food of animal origin; and countries in the Western world, like the United States, often have the highest measured rates of dioxin levels in humans due to their animal-centric diets.

A group of researchers at the Regional Public Health Office in Vejle, Denmark have looked at the role dioxins play in airborne pollution and their link to cancer. They found three methods with which to identify at-risk populations: physical monitoring, environmental monitoring and mathematical modeling. Focusing on the town of Kolding, Denmark in the southern part of the Jutland peninsula, the researchers identified three outlets of dioxin emission, all through chimneys. Knowing the physical location of these sites, they were able to build a computer simulated exposure model using GIS which patterns the effect of the smokestacks’ reach and their impact on the local population.

The air pollution simulation model assessed hourly emissions of airborne pollutants coupled with meteorological and terrain data to better establish patterns of airborne dioxin dispersion. The Danish researchers modeled a 13 year period from 1986-1998, and then compared these results to health reports of the population in the study area. Denmark has kept very stringent medical records on its population since 1968 so all recorded cases of malignant cancer from the study area (except skin cancer) were documented. The study area was broken up into three zones based on the levels of measured airborne dioxins.

At the start of the study, there were 15,000 residents in the focus area, and during the course of the study a total of 46,000 people lived in the focus region. Upon conclusion of the study and data analysis, there was no disproportionate level of cancer found in any of the three focal zones. The levels of dioxins were still of alarm to Danish officials, and thus steps were taken to clean the emissions to reduce dioxin levels. Their key concern was that as airborne dioxins are absorbed into soil and vegetation, they could build up over time and cause future health issues.

In a follow-up study, the highest levels of dioxins were measured in 2000. At this point, the Danish Cancer Register decided to look at occupants of the three zones on a long-term basis to see what, if any, effects the recently increased levels of toxins had on cancer rates in the human population. There are plans to continue the use of GIS in tracking dioxin dispersion; and possibly to extend its use to track population relocation from the affected areas, and to measure cancer rates of former residents as compared to rates of those who have not lived in these impacted areas.

While the current study has not found any noticeable differences in cancer levels due to airborne dioxins, the effects of industrial pollution loom largely over our personal and environmental health. Many other pollutants that are released in industrial manufacturing and production can cause severe health problems. Toxins like sulphur oxides, nitrogen oxides and particulate matter have all been shown to be causes of disease and environmental ruin. The steps the Danish are taking will hopefully provide us with more information on how to lessen our footprint while still maintaining a high level of productivity in this growing world.

Justin Harmon

Staff Writer