Anna Sofía Veyhe1, Dag Hofoss2, Solrunn Hansen3, Yngvar Thomassen4, Torkjel M Sandanger5, Jon Øyvind Odland3, Evert Nieboer6. 1. Department of Community Medicine, Faculty of Health Science, The Arctic University of Norway, Norway. Electronic address: anna.sofia.veyhe@uit.no. 2. Department of Community Medicine, Faculty of Health Science, The Arctic University of Norway, Norway; Institute of Health and Society, University of Oslo, Norway. 3. Department of Community Medicine, Faculty of Health Science, The Arctic University of Norway, Norway. 4. National Institute of Occupational Health (NIOH) , Oslo, Norway. 5. Department of Community Medicine, Faculty of Health Science, The Arctic University of Norway, Norway; Norwegian Institute for Air Research (NILU), Fram Centre, Tromsø, Norway. 6. Department of Community Medicine, Faculty of Health Science, The Arctic University of Norway, Norway; Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
Abstract
BACKGROUND: Although predictors of contaminants in serum or whole blood are usually examined by chemical groups (e.g., POPs, toxic and/or essential elements; dietary sources), principal component analysis (PCA) permits consideration of both individual substances and combined variables. OBJECTIVES: Our study had two primary objectives: (i) Characterize the sources and predictors of a suite of eight PCBs, four organochlorine (OC) pesticides, five essential and five toxic elements in serum and/or whole blood of pregnant women recruited as part of the Mother-and-Child Contaminant Cohort Study conducted in Northern Norway (The MISA study); and (ii) determine the influence of personal and social characteristics on both dietary and contaminant factors. METHODS: Recruitment and sampling started in May 2007 and continued for the next 31 months until December 2009. Blood/serum samples were collected during the 2nd trimester (mean: 18.2 weeks, range 9.0-36.0). A validated questionnaire was administered to obtain personal information. The samples were analysed by established laboratories employing verified methods and reference standards. PCA involved Varimax rotation, and significant predictors (p≤0.05) in linear regression models were included in the multivariable linear regression analysis. RESULTS: When considering all the contaminants, three prominent PCA axes stood out with prominent loadings of: all POPs; arsenic, selenium and mercury; and cadmium and lead. Respectively, in the multivariate models the following were predictors: maternal age, parity and consumption of freshwater fish and land-based wild animals; marine fish; cigarette smoking, dietary PCA axes reflecting consumption of grains and cereals, and food items involving hunting. PCA of only the POPs separated them into two axes that, in terms of recently published findings, could be understood to reflect longitudinal trends and their relative contributions to summed POPs. CONCLUSIONS: The linear combinations of variables generated by PCA identified prominent dietary sources of OC groups and of prominent toxic elements and highlighted the importance of maternal characteristics.
BACKGROUND: Although predictors of contaminants in serum or whole blood are usually examined by chemical groups (e.g., POPs, toxic and/or essential elements; dietary sources), principal component analysis (PCA) permits consideration of both individual substances and combined variables. OBJECTIVES: Our study had two primary objectives: (i) Characterize the sources and predictors of a suite of eight PCBs, four organochlorine (OC) pesticides, five essential and five toxic elements in serum and/or whole blood of pregnant women recruited as part of the Mother-and-Child Contaminant Cohort Study conducted in Northern Norway (The MISA study); and (ii) determine the influence of personal and social characteristics on both dietary and contaminant factors. METHODS: Recruitment and sampling started in May 2007 and continued for the next 31 months until December 2009. Blood/serum samples were collected during the 2nd trimester (mean: 18.2 weeks, range 9.0-36.0). A validated questionnaire was administered to obtain personal information. The samples were analysed by established laboratories employing verified methods and reference standards. PCA involved Varimax rotation, and significant predictors (p≤0.05) in linear regression models were included in the multivariable linear regression analysis. RESULTS: When considering all the contaminants, three prominent PCA axes stood out with prominent loadings of: all POPs; arsenic, selenium and mercury; and cadmium and lead. Respectively, in the multivariate models the following were predictors: maternal age, parity and consumption of freshwater fish and land-based wild animals; marine fish; cigarette smoking, dietary PCA axes reflecting consumption of grains and cereals, and food items involving hunting. PCA of only the POPs separated them into two axes that, in terms of recently published findings, could be understood to reflect longitudinal trends and their relative contributions to summed POPs. CONCLUSIONS: The linear combinations of variables generated by PCA identified prominent dietary sources of OC groups and of prominent toxic elements and highlighted the importance of maternal characteristics.
Keywords:
Food Frequency Questionnaire (FFQ); Persistent Organic Pollutants (POPs); Pregnant women; Principal Component Analysis (PCA); The Northern Norway Mother-and-Child Contaminant Cohort Study (MISA); Toxic and essential elements
Authors: Anthony J F Reardon; Elham Khodayari Moez; Irina Dinu; Susan Goruk; Catherine J Field; David W Kinniburgh; Amy M MacDonald; Jonathan W Martin Journal: Environ Int Date: 2019-05-28 Impact factor: 9.621