expert on environmental toxins
Academy Professor Mirja Salkinoja-Salonen is an internationally
acclaimed expert on environmental toxins. She recalls how she became
interested in the subject in the 1950's:
"Around 1955, Valkeakoski Library acquired the Finnish translation of
Microbe Hunters (Mikrobien metsästäjät) by the Dutchman Paul de Kruif.
That book must have had a tremendous subconscious effect on me, for, as
a student, I applied for a laboratory traineeship in the Netherlands and
nowhere else, although other countries were also available
After having analysed sand and clay at a concrete and tile factory
laboratory in Geldermalsen for some time, I transferred to the huge
(over 2000 employees) laboratory of Shell Chemicals in Amsterdam in
1960. At that time, the Rhine foamed so badly that bubbles would cover
cars on the bridges crossing the river. The City Water Works was faced
with the desperate task of turning this bubble bath into drinking water.
The Shell management assigned to my department, headed by Dr. A.C. van
der Linden (son of the inventor of the pesticide lindane) the task of
finding out why the carbon chains in the synthetic washing agents sold
by the company did not break down but went on foaming long after being
released from washing machines into the sewers.
The research results were a success. We were thrilled to have solved the
mystery in a couple of months: three- or four-branched hydrocarbon
chains were not microbially degradable. Shell immediately switched over
to producing linear or two-branched hydrocarbon chains. It all happened
with amazing speed, in less than a year."
In the 1970's, Salkinoja-Salonen embarked on a research career in
Finland and focussed on the wood-processing industry, and more
specifically, on the biodegradability of chlorinated compounds (chlorine
bleaching of paper pulp, use of chlorophenol in the wood-processing
industry, chlorination of drinking water). She found clear proof of
which chlorinated compounds were microbially degradable and which were
Industry was quick to respond to these research results: the production
of chlorophenol was discontinued in 1984, and in 1991 chlorine was
eliminated from the bleaching process of pulp. "Had someone predicted
this in the 1970's, I wouldn't have believed it. The hardest part was
not convincing the industry, but the authorities..."
In the 1990's Salkinoja-Salonen started studying microbially made toxins
found in indoor building materials, feeds and foods. Her research group
at the University of Helsinki has discovered a new, dangerous bacterial
genera, mitochondriotoxins, that speed up ageing in the human body. A
great challenge is to find out how these toxins and the microbes
producing them can be controlled.
1 Researcher Raimo Mikkola and professor Mirja Salkinoja-Salonen
at a vacuum concentrator, separating toxins from bacteria that have
caused food poisoning. Photo: Olli Oinas
2 Bacillus licheniformis bacterium, that was found in baby food,
has destroyed the cell membranes of spermatozoa,
seen as red in the photo. The bacterium has probably caused
serious food poisonings. Spermatozoa from a pig are particularly
suitable for use as indicator cells for a toxicity test.
Fat-soluble toxins penetrate the cell membranes of spermatozoa
well because of low cholesterol levels of the latter.
Salkinoja's research project