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Environmental contaminants and health


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The research on environmental contaminants and human health encompasses studies of time-trends of organic contaminants in human blood, exposure sources for humans and studies of human health effects of contaminants. We focus on novel study designs utilizing our excellent cohorts available at the department but are also involved in international research projects.

Currently, we pursue three main projects:

  1. Exposure to emerging perfluorinated contaminants in human blood.  
  2. Persistent organic pollutants and type 2 diabetes mellitus- cause or consequence? 
  3. Lead in children and pregnant women in Georgia, Caucasus.

Specific objectives of current and past projects:

  • To study time-trends of persistent organic pollutants in relation to age, period and birth cohorts 
  • To assess the relationship between dietary intake, particularly fish consumption, and blood concentrations of persistent organic pollutants 
  • To address the relationship between persistent organic pollutants and type 2 diabetes using novel study designs 
  • To study temporal and spatial distribution of blood lead levels in pregnant women and children in Georgia, Caucasus 
  • To identify sources of lead exposure for children in Georgia, Caucasus  
  • To assess human exposure to total fluorine, extractable organic fluorine, long chain PFAS and precursor compounds in blood over time and potential effects of PFAS on lipids
  • To assess local food sources as potential routes of exposure to toxic elements from the local nickel smelter in the Norwegian-Finnish-Russian border region
  • Assess exposure to parabens through the use of skin care products and its relation to hormone sensitive cancers
Important publications:
  • Investigating exposure to non-persistent and emerging contaminants 

    Past studies have focused on associations between women’s self-reported use of cosmetic products, especially skin lotion, and the concentrations of parabens in their blood using samples in Norwegian women (Sandanger et al., 2011). Among heavy users of skin care products, the level of parabens in the blood was higher than levels of all other potential environmental pollutants surveyed, and this was one of the first larger epidemiological studies assessing paraben exposure in the general population. 

    In recent years, we have focused on newer perfluorinated chemicals and PhD students Lara Cioni and Ana Carolina Coelho have developed new analytical methods for determining oxidisable PFAS precursors in blood. These methods have enabled us to describe exposure to PFAS through the breakdown of precursor compounds (Cioni et al., 2023). In this effort we revealed that almost all samples investigated from the Norwegian Women and Cancer postgenome cohort had detectable PFAS precursors and results suggested that human exposure to PFAS is underestimated when only long chain PFAS are analysed (Coêlho et al., 2023).

  • Time trends of POPs in blood:

    A longitudinal examination of POPs based on repeated blood samples from the Tromsø Study collected during 1979 to 2007 revealed changing patterns of exposure in Northern Norwegian men. The observed trends demonstrated a general decline in concentrations of polychlorinated biphenyls (PCBs) and pesticides (OCPs) from 1979 to 2007 (Nøst et al., 2013). Further, certain perfluorinated substances (PFAS) initially rose before declining while others showed a steady increase (Nøst et al., 2014). We also studied how PFAS time-trends changed predictors relatively fast in pregnant women (Berg et al., 2014). Our results demonstrated the impact of regulatory actions, such as bans and restrictions on POP production and use, in reducing human POP exposure (Nøst et al. 2017). The studies also indicated that observed trends aligned more with historical emissions than with the age of individuals. Despite the general understanding that these compounds accumulate with age, we showed that if we successfully reduce emissions substantially, concentrations will decline even when you age. The latter was supported by results using a mechanistic exposure model based on emission estimates to predict PCB concentrations based on personal characteristics and lifestyle factors (Nøst et al., 2016). This model could predict time-varying concentrations in individuals, offering alternative exposure metrics, which have been used in our research focusing on POPs and diabetes (Rylander et al., 2015).

    Subsequent research expanded the longitudinal POP data and compared 30-year-olds across time points for POPs (Nøst et al., 2019) and PFAS (Berg et al., 2021). This way we could evaluate how time trends were influenced by the chosen design of the study. The main conclusions were the same, but the time trends were more pronounced in the older men. In summary, these results have demonstrated that regulatory initiatives have impacted human exposures although the response time before human concentrations of a POP are reduced following declining production and use differ between compounds.

  • POPs and type 2 diabetes:

    Using nested case-control studies of type 2 diabetes with multiple pre- and post-diagnostic blood samples from the same individuals, we have assessed the association between POP exposure and type 2 diabetes risk. Current results suggests limited evidence for PFAS or PBDEs being positively associated with type 2 diabetes (Charles et al., 2020, Charles et al., 2023), and that the temporal trend in legacy POPs, such as PCBs and organochlorine pesticides, are different in persons who later develop type 2 diabetes, compared to diabetes-free controls. In fact, it seems like persons who develop diabetes has a slower excretion of POPs, which may indicate reverse causation (Berg et al., 2021, Charles et al., 2022).

  • Georgia and lead: 

    “Lead exposure in children and pregnant women in Georgia” is an on-going project. In 2018, a national survey in Georgia, Caucasus, found that over 60% of children between 2-7 years had blood lead levels (BLLs) above 5 μg/dL. These numbers are alarmingly high as lead may cause damage to the brain and nervous system, especially in young children and fetuses. Lead exposure sources in Georgia are currently not adequately identified, and consequences of high BLLs in children have not been thoroughly assessed. Associations between maternal exposure during pregnancy and BLLs in childhood are not sufficiently studied, although some data exists.

    Since 2014, UiT had an essential role in the creation and implementation of a national birth registry in Georgia. To date this registry covers more than 350,000 deliveries and has resulted in two completed, and four on-going PhD projects, several master theses, and scientific articles. In 2022-2023, researchers at UiT took part in the development and implementation of a national surveillance system for lead in Georgia using cutting-edge technology for blood sampling and analyses of BLLs. Data collection for the surveillance system started in September 2023. Through collaborations, UiT also has access to other lead-related data such as BLLs from over 10,000 mothers and 500 mother and child pairs collected from 2021 to date. This project will make use of both available and continuously collected data on BLLs to study the extent of lead exposure in pregnant women and children in Georgia, geographical differences in BLLs and identify risk factors and possible exposure routes for lead in Georgian children.

Researchers
Ongoing Projects: 

Ana Carolina Coelho: PhD student 

  • Legacy perfluoroalkyl acids and their oxidizable precursors in plasma samples of Norwegian women. Link to publication. Link to publication.
Completed Projects

Lara Cioni: PhD Thesis

  • Fluorine mass balance, including total fluorine, extractable organic fluorine, oxidizable precursors and target PFAS, in pooled human serum from the Tromsø population in 1986, 2007 and 2015. Link to publication.  

Dolley Charles: PhD Thesis

  • Pre- and Post-Diagnostic Blood Profiles of Perfluoroalkyl Acids in Type 2 Diabetes Mellitus Cases and Controls. Link to publication.
  • Longitudinal Changes in Concentrations of Persistent Organic Pollutants (1986–2016) and Their Associations with Type 2 Diabetes Mellitus. Link to publication.
  • Polybrominated Diphenyl Ethers in Type 2 Diabetes Mellitus Cases and Controls. Link to publication.

Vivian Berg: PhD Thesis

  • Maternal serum concentrations of per- and polyfluoroalkyl substances and their predictors in years with reduced production and use. Link to publication. 
  • Assessing the relationship between perfluoroalkyl substances, thyroid hormones and binding proteins in pregnant women; a longitudinal mixed effects approach. Link to publication. 
  • Persistent organic pollutants and the association with maternal and infant thyroid homeostasis; a multipollutant assessment. Link to publication. 

Therese Haugdahl Nøst: PhD Thesis

  • Estimating Time-Varying PCB Exposures Using Person-Specific Predictions to Supplement Measured Values: A Comparison of Observed and Predicted Values in Two Cohorts of Norwegian Women. Link to publication.
  • Repeated Measurements of Per- and Polyfluoroalkyl Substances (PFASs) from 1979 to 2007 in Males from Northern Norway. Link to publication.
  • Persistent Organic Pollutants in Norwegian Men from 1979 to 2007: Intraindividual Changes, Age–Period–Cohort Effects, and Model Predictions. Link to publication.

Charlotta Rylander: PhD Thesis

  • Dietary Predictors and Plasma Concentrations of Perfluorinated Compounds in a Coastal Population from Northern Norway. Link to publication.
  • Dietary Patterns and Plasma Concentrations of Perfluorinated Compounds in 315 Norwegian Women. Link to publication.
  • Perfluorinated Compounds in Delivering Women from South Central Vietnam. Link to publication.
Other Key Publications: