“Teenagers today are still accumulating organochlorine compounds in their body”

26/11/2014

Although from 70-80 years in most countries banned the production and use of organochlorine compounds (OCs), it still detect traces of these toxic chemicals in the body of the young people today. This is the conclusion of a study done by researchers from CREAL, ISGlobal research center, in collaboration with the Department of Environmental Chemistry from IDAEA-CSIC.

The study included data from 100 children from Ribera d’Ebre and 480 from Menorca, all of the INMA Project, a national project that aims to assess the impact of the environment on children in Spain.

Because the levels of OCs in the environment have decreased substantially since the banning, the aim of the study was to assess whether this reduction over time was also given to adolescents today. Therefore, blood samples were obtained from participants at birth, 4 years and 14 years and they are measured several OCs including β-HCH, HCB, DDE (product of the pesticide DDT) and several PCBs. The study shows that the total burden of PCBs and DDE in serum is above the age of 14 years at the time of birth. This is due mainly to the diet, which today is the main source of exposure to these compounds. The study also shows that the levels of these compounds were higher in children who were breastfed during the first months of life.

Despite the results, the researchers recommend mothers to breastfeed their children, because breast milk provides more benefits compared to the potential damage of these substances. We also emphasize that the levels detected in children from Ribera d’Ebre and Menorca are similar to those observed in other European countries or North America. Therefore, it is not a local but a global issue.

Dr. Gascon, lead author of the study, highlights the persistence of these substances in adolescents despite the banning for many years and warning the situation in developing countries where DDT is still used as an insecticide to control the mosquitos and malaria. She adds that “it is very important to work on finding effective alternatives to the use of DDT.”

Organochlorine compounds (OCs)

Organochlorine Compounds (OC) belong to the Persistent Organic Compounds (POC) for their presence in the whole planet, their biostability and their slow biodegradation, their accumulation in adipose tissue and their long average life. As per their name, the OC are chemical organic compounds which have substituted some or the totality of their hydrogen atoms for chlorine.

The production and the intensive use of these compounds began in the 30s in industrial processes, like the production of insulators, and agriculturists (like pesticides). Many of these compounds are now prohibited, but they are still present due to their slow biodegradation and their use in the developing countries. The benefits of these compounds, such as synthetic pesticides, are undeniable but the preoccupation by their possible adverse effects on the human health in a long term basis has lately increased. These compounds have an average life of 10 years or more, and, thanks to their chemical properties, they have a great capacity to arrive to remote zones; they can be transported through the atmosphere and to be accumulated in the organic matter of the ground and in the live organisms.

The OC have dispersed and distributed throughout the entire planet. In human beings, the path of exposure is the rich fat diet, and several studies have shown that many of habitual consumption food in Spain (meat, fish, eggs, milk and derivatives) contain p, p’DDE, PCBs, HCB and isomers of HCH. The water air and consumption are also routes of environmental exposure. OC are stored in rich fat organs, like the liver or the brain, and also in serum or maternal milk. These compounds pass the placental barrier, and the breastfed babies incorporate them 20 times more than the adults. In the first three months of life they get to accumulate 6{3effe4377b6f02be2524d084f7d03914ac32a2b62c0a056ca3444e58c1f10d0b} of everything that will be accumulated during the rest of their lives.

Some studies made in new born babies to evaluate the possible effects of these compounds in populations exposed at the habitual levels of the developed world have proved a slight association between the prenatal exhibition to PCBs and the growth and later the motor and cognitive development. In adults, the exposure to OC has been associated with cancer, cardiovascular disease and endocrine alterations (majorly alterations in the thyroid system).

Referencia: Gascon M, Vrijheid M, Garí M, Fort M, Grimalt JO, Martinez D, Torrent M, Guxens M, Sunyer J. Temporal trends in concentrations and total serum burdens of organochlorine compounds from birth until adolescence and the role of breastfeeding. Environ Int 2015; 74: 144-151.