In most large cities within the United States, it is quite ‘clear’ that we are having grimy stuff accumulate. Perhaps it is most noticeable on the kitchen counters and windows as they are supposed to be very clean and clear. 

In the June issue of Journal of Environmental Science and Technology, a group of researchers from the University of Toronto, Canada reported that they have found that “the surfaces of windows and roads contain tiny amounts of long-banned toxic contaminants like PCBs.”

What these researchers state through this technical paper is that this grime, which we find on the outside of our homes, contains a lot of toxic chemicals. These are chemicals which we breathe and which get into our water system, including nearby creeks and rivers. 

The study, the basis for these conclusions, involved the collection of samples taken in the urban areas of Baltimore, Maryland USA, Toronto, Canada, and the southern part of Ontario, Canada.

The type of toxic compounds which the research team found were typical of the toxins emitted by furnaces, power plants, manufacturing facilities, and vehicle exhausts. In this grime residue, however, the researchers also found things like DDT. Since DDT has long been banned in this part of the world, it is most probable that such a very toxic chemical is traveling with wind currents from far away places. Yes, there are places where these chemicals are still being manufactured and still being used. 

The lead author of this study was Miriam L. Diamond, who has a PhD, and also is an associate professor at the University of Toronto. She provides us with this advice. “It is still quite controversial whether the chemicals we found in the urban grime during this study is capable of causing cancers or other serious health defects.”

She then added: “It would be good to be careful about growing vegetables in contaminated soil and to wash all produce thoroughly. It also is important to keep toddlers from eating dirt, which they tend to do.”

(Journal of Environmental Science and Technology, June 2000)