Blood Metal Concentrations of Manganese, Lead, and Cadmium in Relation to Serum Ferritin Levels in Ohio Residents

Abstract

The objectives of this study were to assess ferritin-specific profiles of blood metal concentrations such as manganese, lead, and cadmium and to evaluate whether ferritin may affect the behavior of the blood metals in relation to menstruation, menopause, or sex in Ohio residents. Recruited participants included residents from Marietta, East Liverpool, and Mt. Vernon, OH, USA, who were aged 30-75 years and lived at least 10 years in their respective town. The levels of the neurotoxic metals such as manganese, cadmium, and lead were assayed in whole blood. Serum was analyzed for ferritin level [as a biomarker of iron (Fe) status]. An association between blood metal concentrations and independent variables (age, serum ferritin, manganese exposure status, and sex) by multiple regression analysis was assessed, controlling for various covariates such as BMI, educational level, smoking, and alcohol drinking status. Overall, the geometric means of blood manganese, cadmium, and lead levels of all participants (n = 276) were 9.307 μg/L, 0.393 μg/L, and 1.276 μg/dL, respectively. Log serum ferritin concentrations were inversely associated with log blood manganese concentration (β = -0.061 log ferritin and β = 0.146 categorical ferritin) and log blood cadmium concentrations (β = -0.090 log ferritin and β = 0.256 categorical ferritin). Log serum ferritin concentrations were not associated with log blood lead concentrations. Variables of age, sex, and exposure status were not associated with log manganese concentrations; however, log blood cadmium concentrations were higher in older population, women, and smokers. Log blood lead concentrations were higher in older population, men, and postmenopausal women. Our study showed that iron deficiency is associated with increased levels of blood manganese and cadmium, but not blood lead, in Ohio residents. These metals showed different toxicokinetics in relation to age, sex, and menopausal status despite similar relationships between ferritin and metal concentrations.

Environmental exposure to manganese in air: Associations with cognitive functions

“…Furthermore, average blood concentrations of Pb, Hg and Cd in this study population were also within the ranges observed in the general population of the U.S. (Kim et al, 2015). …”

“…However, mean blood Mn levels were within the average range of the general population (CDC, 2005; Kim et al, 2015). Analyses of Mn in diet, from the residents’ health questionnaire, indicated no significant differences between the two towns in the amount of Mn consumed in foods.…”

Determinants of serum manganese levels in an Italian population

“…Consistently, when we performed a regression model between meat intake and Mn levels, the inclusion of iron intake in the model toned down the observed inverse relation (data not shown). Also, serum ferritin has been noted to be inversely associated with blood Mn concentration (56). Finally, in out study tea and chocolate consumption was not associated with the serum Mn levels, although about one third of the study participants reported no tea consumption, so weakening our possibility to find any association.…”

Medication use associated with exposure to manganese in two Ohio towns

“…This methodology is further described in previous manuscripts (Bowler, Kornblith, et al 2015; Kim et al 2015). …”

“…In recent decades, adult environmental studies of Mn exposure have reported physical (Santos-Burgoa et al 2001; Haynes et al 2010; Kim et al 2015) and mental health problems identified through cognitive (Bowler, Kornblith, et al 2015), mood (Bowler et al 2012), motor, and neurological (Rodríguez-Agudelo et al 2006; Kim et al 2011; Bowler, Beseler, et al 2015) testing of study subjects, but medical record reviews for exposed residents are rare in the literature. When medical records and clinical testing are unavailable, examination of residents’ current prescribed medication use (Dayal et al 1994; Zmirou et al 1994; Bowler et al 2002) has been used as a proxy of health effects associated with Mn or other neurotoxic chemical exposures.…”