People are exposed to chemicals at every moment
Ljubljana, 30 December - People are constantly exposed to chemicals which enter their bodies from the environment. Some are known to have harmful effects, for others the jury is still out. Phthalates, a class of hormone disruptors, are among the better known and more common ones. Researchers have even found prohibited pesticides in human samples.
There are millions of chemicals that can enter an organism through food, water and even inhaled air. "We are exposed to chemicals at any moment. With every glass of water we ingest something that we would not want to. With every piece of plastic, with any food packaging, some compound or other enters our body. The degradation products of these compounds, metabolites, cause disease in people," says Tina Kosjek, pharmacist and researcher at the Department of Environmental Sciences at the Jožef Stefan Institute, where she is researching human exposure to environmental impacts.
Researchers are aware of and track many chemicals, such as heavy metals, persistent organic pollutants and worrisome new chemicals that are present everywhere but poorly researched, like acrylamide, bisphenol a, and parabens.
Some of them are known to cause hormonal imbalance and auto-immune diseases like rheumatoid arthritis, thyroid diseases, type 1 diabetes, asthma and allergies, or affect the development of cancer. The effects on human health of many other chemicals remain unknown.
Researchers are mostly concerned about the many still unknown chemicals in the environment. It is estimated that more than 90% of them fall into this category. Their existence is known only indirectly, through their effect on human health. Recognizing chemicals in the environment and in human samples is key in evaluating the effects on the health of humans and other organisms, says Kosjek.
Phthalates, known hormone disruptors, are everywhere around us
The Department of Environmental Sciences has been researching the exposure of humans to many organic chemicals. They are also part of the national human bio-monitoring programme and regularly analyse samples from children and adolescents. They measure the concentration of chemicals in blood, urine, saliva, semen, exhaled air, breast milk, hair, nails and other tissues.
The researchers are usually looking for already known target compounds, such as phthalates. These compounds are artificially made and most often used as softeners in the plastic industry. They do not bind with plastics and so easily leech into the environment. Certain phthalates are known to disrupt hormones.
According to Kosjek, phthalates are everywhere, they are present in plastic, food packaging, medicine, cosmetics. From these products phthalates enter the environment. They are then ingested, absorbed through the skin or inhaled if bonded with dust particles. "We know that micrograms of phthalates per litre swim in our blood, which is quite scary. The question is how many other compounds are in there that we don't even know of."
Exposure to phthalates already in the womb
Exposure to phthalates begins when the foetus is still in the womb. Phthalates can enter the foetus through umbilical cord blood, while a baby can ingest them with breast milk. Currently the department is researching breast milk samples as part of a master's thesis to research the phthalate exposure of Slovenian newborns.
They have studied phthalate exposure with urine samples and found that exposure of children and adolescents in Slovenia is comparable to findings for Europe and the world. They have also examined how sensitivity to phthalates related to genetics. They were the first to find that individuals with certain genetic changes metabolise phthalates slower. Those individuals are exposed to higher amounts of harmful substances for longer periods of time and consequently more susceptible to harmful effects of phthalates, which Kosjek finds worrisome.
Kosjek and other researchers published these findings in the Environment International magazine. The article was chosen as one of the Great in Science by the Slovenian Research Agency.
It is difficult to make any conclusions, says Kosjek, since there is always a mixture of many compounds in the environment, and we don't know most of them yet.
Prohibited pesticides also found in samples
Though they usually look for known compounds, the researchers recently analysed unknown components in samples. "In other words: we did not know what we were looking for," says Kosjek.
What they found in the samples surprised them. There were pesticides that are prohibited in the region, for example the herbicide atrazine, or have limited use, like the insecticides amitraz and diazinon. "We can really only guess where the pesticides came from. It could be old stocks. The fact remains that they were found in groundwater."
The research will be expanded with sampling in the broader population and by using different analysis methods to gain more information on other compounds. "There are a million other [compounds] we can connect our findings with. This is a research that continues," says Kosjek.
Changes in environment are concerning
When asked if the results of her research worry her, Kosjek says that she is mostly concerned with the evident changes in the environment. "Why is there so much cancer, allergies, rheumatic diseases? This is in part thanks to improvements in diagnostics, but in part there are more and more of these diseases and conditions. What is the cause? What are we exposed to? What are we doing wrong that this is happening?" Kosjek wonders.
She is aware that the increase in diseases is also related to longer life expectancy. "But allergies in children are caused by environmental factors and lifestyles, which are not as they were in the past. That is what worries me," Kosjek says.
There are many contributing factors. "We are much more exposed to stress, we are always in a hurry, we forget that we have to breathe and move, that we have to eat healthy; our food today is highly processed and more artificial, even if it is more diverse thanks to globalisation. With that come pesticides and phthalates from packaging plastics. That is what has changed from fifty years ago when people were eating porridge."
But that does not mean that we have to give up everything, Kosjek noted. "We have to find balance. Live healthy in a different way. If we breathe healthy air, stay active, eat well, we will be able to eliminate these substances in a different way."
Harmful chemicals are mostly present at low concentrations in the environment and food, so long-term exposure poses more problems than one-time exposure, says Kosjek. "The chemicals that are proven to be harmful to people are well controlled. I believe the most we can do for our health is to have a healthy lifestyle, avoid extremes, and trust the experts."
New high-performance mass spectrometer at the Institute
In the future they hope to research the connection between substances in the environment and diseases with the help of a new high resolution mass spectrometer, the Orbitrap Exploris 240, that the department has recently acquired.
Kosjek is the administrator of this and other spectrometers in the department. It is her responsibility to ensure that the instruments work correctly and to offer support to students and other researchers in developing new methodologies.
This spectrometer is one of the biggest challenges for Kosjek. "If we want to use what the machine has to offer, we have to work together. Communication, understanding and learning new methods take a lot of effort," says Kosjek who is very excited to work with the new device.
Mass spectrometers measure molecules, from the smallest like formic acid to the largest like proteins. Molecules can be sorted and counted which provides data on the identity and the amount of a compound in the material.
The new spectrometer to analyse what has only been a dream until now
The new spectrometer is far ahead of other spectrometers that the department is already using. It can determine molecular mass with great accuracy. It is highly sensitive and can determine extremely low amounts of compounds.
"From now on we will be able to take on projects from fields that we could not even dream about before, researching connections between diseases and chemicals in us," says Kosjek, hopeful that they will be able to provide support in drug development in the future.
They will be able to detect many different pollutants and link the findings to genetic analyses, which are also the subject of their research. Genetic analysis can offer data on susceptibility for a certain disease, as well as enable research on the effects of metabolism speed and excretion of chemicals and indirectly the sensitivity to chemicals from the environment. That opens new possibilities for research of the environmental effects on health and connecting findings of different studies.
"When we know more about links between residual chemicals in the environment and diseases, we will be able to limit exposure to chemicals and prevent or ease the treatment of diseases," says Kosjek.
The department wants to further research Alzheimer's disease, which is known to correlate with environmental effects. "I hope we will be able to help develop the link between environmental effects and Alzheimer's disease. But that is a process that takes years of research and cooperation of experts from many fields," says Kosjek.
"There are millions of substances and compounds that we might never identify, so it will be difficult to point fingers at one that affects the development of a disease." They hope that they will find a combination or a profile of compounds that will provide answers.
They will also research the effectiveness of bleomycin, which is used to treat cancer. The spectrometer will also be used in bioremediation, an effective, easy and efficient method of cleaning the environment that uses microorganisms to decompose pollutants in a contaminated area. The machine will monitor pollutant decomposition to check the effectiveness of the process.
Hopeful that research will help people in the future
There are many questions left for science to answer, says Kosjek. If she can say at age 80 that she helped develop a cancer cure or helped science understand the causes of a disease and that she helped someone, improved someone's quality of life, she will be happy.
Kosjek believes that although research and science communication are important, implementing findings in practice is essential and it is where science is often lacking.