The concerning findings were accidental, with the scientist who made it finding a lot more than he was expecting. "I sent a milk sample to be tested in the lab, as part of research that tried to identify residue of a certain chemical in it," Shimshoni said.
The test showed that the milk didn't contain the suspected chemical, but according to Shimshoni, "the sample contained many other chemicals that made me say, 'Wow, what's going on here?'"
After realizing that further research was needed, Shimshoni reached out to fellow colleagues, and together with researchers from the Hebrew University's Faculty of Agriculture, he recently published his research that sheds light on the actual substances that can be found in milk produced and sold in Israel.
The research included testing 51 dairy and goat milk cartons produced by three of the leading companies in the market. The results showed that every single milk carton that was checked contained at least one pollutant, either medication or pesticide residue, and often up to five similar chemicals in one carton.
Eight different pesticides used for exterminating insects were found in the milk. According to the researchers, this is most likely due to the fact that the food given to cattle is sprayed with these materials.
Out of 17 medicine samples tested for, the residue of three was found in the milk: ibuprofen, a common painkiller; bezafibrate, a prescription drug for lowering cholesterol and triglyceride in the blood; and caffeine. The leading assumption is that the medicine residue also originated from food given to cows and goats, as a large proportion of it is watered with recycled sewage water that may contain medicine residue despite the comprehensive filtration process it goes through.
While the concentration levels of the substances found in the milk are relatively low, they are still reason for concern, according to Shimshoni. Higher levels could be found in different periods of time, but it's impossible to know for certain as the issue was never monitored. "It's very likely, for example, that in different seasons more pesticides are used in the fields, which would increase their concentration in the food given to cattle and, eventually, in the milk they produce."
But milk may not be the only way of being exposed to these substances. "People who drink milk usually consume other dairy products such as yogurts and cheese," Dr. Hagit Olonevsky, a healthcare risk manager, added. Such products were not tested in the new research and it is unknown whether or not they contain the same contaminants found in milk. And according to Shimshoni, "some of these substances can be found in the fruits and vegetables we consume," and that we need to check if the growing exposure from the different sources may add up to problematic concentrations.
Israeli law does not refer to the maximum levels allowed in milk for the substances that were found by Shimshoni's team. Although the levels of concentration are relatively low by European standards, Olonevsky believes that "we have to define the maximum levels of concentration allowed in our milk for these substances," and that "it makes no sense that there's a dangerous chemical in our milk and we're not limiting it."
Shimshoni believes the solution will come as people become more aware of the unknown materials in their milk. "We should be diverting the attention of those responsible for the public's health," and that "we also need to take better care of the animals in the industry and their food, because whatever we do to animals will eventually reach our plates."
Olonevsky on the other hand, believes that more investments need to be made in researching the subject, in order to find creative solutions for lowering the diversity and concentration of milk contaminants, especially because the use of recycled sewage water for agriculture use is very popular in Israel.
Other theoretical solutions may include technological applications. "Maybe the contaminants can be actively extracted from the food given to animals," Olonevsky concludes. "What I do know is that ignoring the problem is not a solution."
The Agriculture and Rural Development Ministry commented by saying that the public faces no danger as the concentration of the mentioned materials is low, adding that the contamination probably originated with the water used for watering the fields, which falls under the responsibility of the Health Ministry.
The Health Ministry, in turn, stated that examining biological residue and pesticides in milk is done by the Agriculture Ministry, and that according to the conclusions of specialists, the exposure to the residue found is low and inconsequential.