About FELIX
One Exposure – One Health
The FELIX-project will collect important information on PFAS exposure
The strategy of FELIX is within the framework of “One Exposure – One Health”, which is the collaborative effort of multiple disciplines to attain optimal health for people, animals and the environment. Several studies have shown that pet cats are excellent sentinels for human exposure to chemicals from the indoor home environment. Many organic chemicals originating from human activity (anthropogenic) may act as endocrine disrupting chemicals (EDCs). EDCs interact with hormones in organisms, leading to various endocrine disease-related endpoints, for example diabetes mellitus (DM), endocrine related cancer, immune, thyroid and neurodevelopmental disorders. These diseases have been increasing both in humans and animals the last decades.
Due to cats’ preference for routines and the limited environment in which cats live, it is easier to find cause-effect relationships between indoor contaminants and health in studies involving cats, compared to in human epidemiological studies. In addition, cats and humans share similarities in the mechanistic development of several endocrine diseases.
Background
Environmental pollutants in cat blood
FELIX builds on a previous FORMAS-funded project that investigated the exposure of thyroid-disrupting substances in the blood of cats (MiSSE). The chemicals analyzed were the halogenated persistent organic pollutants listed under the Stockholm Convention, such as pesticides used in the past (DDT, pentachlorophenol, lindane, etc.), the industrial chemicals polychlorinated biphenyls (PCBs) and flame retardants, but also chemicals used today, such as the plasticizers phthalates. Cats had the highest levels of PFAS substances in their blood, something that is also seen in the blood of humans. We also reported in MISSE that the levels of endocrine disruptors in the blood of cats and humans were close to potential effect levels for thyroid hormone disruption. The results are alarming as one can expect both higher concentrations and more chemicals in the blood of individuals depending on their life style. Thyroid hormones are involved in many cellular processes and are important for normal development and growth during childhood and a maintained metabolism throughout life. Disturbances in thyroid hormone levels can cause several health problems, especially during early developmental stages.
Focus
FELIX will examine sick and healthy cats and look for associations to PFAS exposure
Health effects
PFAS exposure has been linked to hormone disruption
PFASs desirable properties, i.e. high surface activity due to their lipophobicity and hydrophobicity, combined with extreme resistance to chemical and biological degradation has led to a broad application of PFASs in industrial and commercial products. Due to the extensive use and the persistence of the chemicals (aka “forever chemicals”) high levels can be found everywhere in our surrounding environment. There are several in vitro/vivo reports on the toxicity of PFASs, and human epidemiological studies are now reporting observations on e.g. altered thyroid hormone blood levels and effects in later childhood stages associated with early life exposure (e.g. adiposity and immune suppression). Low birth weight, decrease in antibody response at vaccination in children and increased cholesterol levels were considered as critical effects when setting the new health-based guidance levels for PFOS and PFOA, suggested by the European Food Safety Authority (EFSA) in 2018.
work packages
Project outline
Within FELIX, we will analyze cats’ blood for a large number of different PFAS substances to identify which are the most problematic. The cats will be selected based on their health status, such as hyperthyroidism (overactive thyroid), diabetes mellitus, and healthy. With the help of a broad characterization of the cats’ health status, as well as PFAS exposure, FELIX will be able to map the mechanisms of action that lead to the hormonal disorders. Previous studies have shown that many hormonal systems have been conserved and that the mechanisms are similar in different species. Therefore, many results in FELIX will be able to be extrapolated to general conditions for humans.
The work packages (WPs) of FELIX are outlined in the figure above. The project relies on a high-quality sample collection (WP1), where effort will be invested to minimize the variance and strengthen the statistical power of the results. Blood serum and cat hair will be collected from cats that are engaged while visiting the clinics. Volunteers will be recruited through different channels (social media, networking, relevant organisations etc.) and will be asked to collect cat hair, household dust and cat food. Information on the process is available in sampling ca (LINK TO SAMPLING CAMPAIGN).
Routine biological analysis and clinical examination will be combined with comprehensive chemical analysis of several matrices to produce a valuable dataset for investigation (WP2). By studying several endocrine related biomarkers, we will identify links between PFAS exposure and adverse health outcomes (WP3). Effort will be in establishing a non-invasive sampling protocol for the establishment of cats’ home environment in the sense of chemical exposure and chronic stress (WP4).
Project team
Who we are
Assoc. Prof.
Jana Weiss
Dept. Environmental Science, Stockholm University.
Jana is an environmental chemist who has worked with cats’ exposure to environmental pollutants and linked it to various hormonal disorders since 2012. She is specifically interested in combining toxicological studies with chemical analysis and risk assessment of complex chemical mixtures.
Assoc. Prof.
Bodil Ström Holst
Clinical Sciences, Swedish University for Agriculture, Uppsala.
Bodil is a licensed veterinarian, has a PhD in obstetrics and gynecology and is an associate professor of reproduction. She is a senior lecturer in the health and diseases of pets, especially dogs and cats. Among other things, her research is in diabetes mellitus in cats and challenges in immunological diagnostics.
PhD student
Ninni Rothlin Zachrisson
Clinical Sciences, Swedish University for Agriculture, Uppsala.
Ninni began her research studies in feline diabetes in February 2020. She has been a licensed veterinarian since 2014 and has worked as a clinic veterinarian at the University Small Animal Hospital, with intensive medicine and above all feline medicine as her main interests. She was the University Animal Hospital’s cat ambassador (via the International Society of Feline Medicine) between 2016-2020.
PhD student
Dandan Zhao
Dalian University of Technology, Kina
Dandan has a Master’s degree in Environmental Science and Engineering from the Dalian University of Technology, China. Her interest is within the One Health concept, and especially studying pet animals. Chemical exposure has implications to both animal and human health. She believes that FELIX offers a unique opportunity to contribute to a more comprehensive understanding of endocrine diseases, while also advancing the ethical use of animals in research.