This is the main conclusion of a new study by the Barcelona Public Health Agency (ASPB) and the Institute of Marine Sciences (ICM-CSIC) recently published in Journal of Hazardous Materials.
A study by the Barcelona Public Health Agency (ASPB) and the Institut de Ciències del Mar (ICM-CSIC) in collaboration with the Doñana Biological Station (EBD-CSIC) and the Catalan Institute of Ornithology (ICO) has evaluated for the first time the presence of persistent organic pollutants in yellow-legged gulls living in Barcelona and the possible consequences for their health. Specifically, it has been analysed how exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) affect the physiology of the species. On the other hand, it has also been identified, by tracking urban gulls with GPS devices, the areas of greatest exposure to these pollutants, such as clean points, industrial areas or the city itself. The results have been recently published in the scientific journal Journal of Hazardous Materials and reveal the key role that yellow-legged gulls, which inhabit densely populated and industrialized urban areas, can play as sentinels of pollution in large cities.
Persistent organic pollutants are toxic substances that pose a threat to the health of living beings and the environment. They persist for a long time, are bioaccumulative, have harmful effects and can be transported to places where they have not been produced. In particular, PCBs and PBDEs have been used in industrial production. Although today their use is restricted or banned, they are very present in cities, as they can still be found in waste from plastic products, textiles or other products such as electrical equipment, vehicles, furniture, etc.
For the preparation of this work, the ASPB laboratory analysed blood samples from several seagulls to identify the presence of these contaminants. On the other hand, the ICM-CSIC scientific team evaluated 27 physiological parameters and biomarkers related to the body's protection against chemical pollutants, health and eating habits. "The results of our analyses have shown a high exposure to PCBs, but also to PBDEs in the yellow-legged gulls that inhabit Barcelona," explains Núria Cortés-Francisco, researcher at the ASPB. In this regard, one aspect to highlight is that "the male specimens that have not yet reached sexual maturity are the ones that show a greater physiological response linked to PCB and PBDE content. One possible explanation is the use of landfills as a food source and a greater use of marine resources, areas associated with a higher concentration of pollutants subjected to analysis," adds David Nos, predoctoral researcher at the ICM -CSIC.
"The combined use of chemical analysis and pollution markers, together with GPS tracking of some individuals, has allowed us to understand the consequences for gulls of inhabiting a city like Barcelona. All this is an effective tool to know the origin, the degree of exposure and the effects of these chemicals," says Joan Navarro, ICM-CSIC researcher.
Persistent organic pollutants interfere with the reproductive and immune systems of mammals, fish and birds through endocrine disrupting effects and suppression of the immune system. There is scientific evidence that in birds PCBs and PBDEs can cause delays in egg and egg-laying development, alterations in gene expression, neuronal disorders, deformities and reduced orientation ability. Taken together, all of these effects resulting from the ingestion of residues can eventually have repercussions on the normal development of the entire population.
The parameters analyzed confirm the physiological response of the organism to these pollutants, for example, through the inhibition of enzymes such as carboxylesterases, which are responsible for protecting the organism from certain chemical compounds.
In addition, high levels of markers of liver and kidney damage have been detected, as well as high levels of cholesterol in adult individuals, a risk factor for suffering from arterial diseases and atherosclerosis, associated with a poor-quality diet.
A study by the Barcelona Public Health Agency (ASPB) and the Institut de Ciències del Mar (ICM-CSIC) in collaboration with the Doñana Biological Station (EBD-CSIC) and the Catalan Institute of Ornithology (ICO) has evaluated for the first time the presence of persistent organic pollutants in yellow-legged gulls living in Barcelona and the possible consequences for their health.
Specifically, it has been analysed how exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) affect the physiology of the species. On the other hand, it has also been identified, by tracking urban gulls with GPS devices, the areas of greatest exposure to these pollutants, such as clean points, industrial areas or the city itself. The results have been recently published in the scientific journal Journal of Hazardous Materials and reveal the key role that yellow-legged gulls, which inhabit densely populated and industrialized urban areas, can play as sentinels of pollution in large cities.
Persistent organic pollutants are toxic substances that pose a threat to the health of living beings and the environment. They persist for a long time, are bioaccumulative, have harmful effects and can be transported to places where they have not been produced. In particular, PCBs and PBDEs have been used in industrial production. Although today their use is restricted or banned, they are very present in cities, as they can still be found in waste from plastic products, textiles or other products such as electrical equipment, vehicles, furniture, etc.
To carry out this work, the ASPB laboratory analysed blood samples from several seagulls to identify the presence of these contaminants. On the other hand, the ICM-CSIC scientific team evaluated 27 physiological parameters and biomarkers related to the body's protection against chemical pollutants, health and eating habits.
"The results of our analyses have shown a high exposure to PCBs, but also to PBDEs in the yellow-legged gulls that inhabit Barcelona," explains Núria Cortés-Francisco, researcher at the ASPB.
In this regard, one aspect to highlight is that "the male specimens that have not yet reached sexual maturity are the ones that show a greater physiological response linked to PCB and PBDE content. One possible explanation is the use of landfills as a food source and a greater use of marine resources, areas associated with a higher concentration of pollutants subjected to analysis," adds David Nos, predoctoral researcher at the ICM -CSIC.
"The combined use of chemical analysis and pollution markers, together with GPS tracking of some individuals, has allowed us to understand the consequences for gulls of inhabiting a city like Barcelona. All this is an effective tool to know the origin, the degree of exposure and the effects of these chemicals," says Joan Navarro, ICM-CSIC researcher.
Persistent organic pollutants interfere with the reproductive and immune systems of mammals, fish and birds through endocrine disrupting effects and suppression of the immune system. There is scientific evidence that in birds PCBs and PBDEs can cause delays in egg and egg-laying development, alterations in gene expression, neuronal disorders, deformities and reduced orientation ability. Taken together, all of these effects resulting from the ingestion of residues can eventually have repercussions on the normal development of the entire population.
The parameters analyzed confirm the physiological response of the organism to these pollutants, for example, through the inhibition of enzymes such as carboxylesterases, which are responsible for protecting the organism from certain chemical compounds.
In addition, high levels of markers of liver and kidney damage have been detected, as well as high levels of cholesterol in adult individuals, a risk factor for suffering from arterial diseases and atherosclerosis, associated with a poor-quality diet.
"The set of results highlight the key role played by seagulls as sentinels for monitoring environmental health, and specifically chemical pollution in coastal urban areas, putting in value the need to deepen these analyses, which can be key to perform environmental prevention and ensure the welfare and collective health", states Tomás Montalvo, ASPB researcher.
Despite current restrictions, these organic pollutants continue to affect the environment, and urban and industrial areas have the highest levels of exposure. In view of this scenario, the authors of the study highlight the need to further explore the dynamics of pollutants in these areas. In this sense, they point out that "the continuous monitoring of individuals with GPS could allow a more agile detection of changes in exposure to pollutants". They also stress that a better understanding of the response of different biomarkers is needed to provide a more complete picture of the effects of pollutants on biological systems. "This approach is critical to better understand the complexities of the interaction between environmental pollution, human health, and ecosystem health," they conclude.