Impact of ferromanganese alloy plants on household dust manganese levels: Implications for childhood exposure

Abstract

Adolescents living in communities with ferromanganese alloy plant activity have been shown to exhibit deficits in olfactory and fine motor function. Household dust may serve as an important manganese (Mn) exposure pathway to children, though dust Mn concentrations have not previously been measured to assess household contamination from ferromanganese alloy plant emissions. Here we determined the association between dust concentrations and surface loadings of Mn and other metals (Al, Cd, Cr, Cu, Fe, Pb, and Zn) in indoor and outdoor household dust from three Italian communities that differ by history of ferromanganese alloy plant activity: Bagnolo Mella, with an active ferromanganese alloy plant (n=178 households); Valcamonica, with historically active plants (n=166); and Garda Lake, with no history of ferromanganese plant activity (n=99). We also evaluated Mn levels in other environmental (soil, airborne particulates) and candidate biomarker (blood, hair, saliva, fingernails) samples from children within the households. Household dust Mn concentrations and surface loadings were significantly different between the three sites, with levels highest in Bagnolo Mella (outdoor median Mn concentration = 4620, range 487 – 183,000 µg/g), intermediate in Valcamonica (median = 876, range 407 – 8240 µg/g), and lowest in Garda Lake (median = 407, range 258 – 7240 µg/g). Outdoor dust Mn concentrations in Bagnolo Mella, but not the other communities, were significantly inversely related with distance from the plant (R2=0.6630, P<0.0001). Moreover, outdoor dust Mn concentrations and loadings were highly predictive of but significantly higher than indoor dust Mn concentrations and loadings by ~2 to ~7-fold (Mn concentrations) and ~7 to ~20-fold (Mn loadings). Finally, both indoor and outdoor dust Mn concentrations and outdoor dust Mn loading values were highly significantly correlated with both soil and air Mn concentrations, and with children’s hair and fingernail Mn concentrations, but weakly or not associated with saliva or blood Mn levels. Given the evidence associating elevated Mn exposure with neurological impairments in children, these data support that dust Mn levels should be reduced in contaminated environments to protect the health of resident children.

Polymorphisms in manganese transporters show developmental stage and sex specific associations with manganese concentrations in primary teeth

“…Mn exposure of these children has been carefully monitored by measurements of Mn concentrations in samples from the their home environment and shown increased Mn concentrations in samples from the Valcamonica and Bagnolo Mella compared to Lake Garda (Borgese et al, 2011, 2013; Lucas et al, 2015). The children have also undergone comprehensive neurological and neuropsychological testing at adolescent age, including tests for IQ, motor function and behaviour; however, neurological outcomes were not in included in the present study.…”

Sex differences in sensitivity to prenatal and early childhood manganese exposure on neuromotor function in adolescents

“…All samples were stored at 4 o C until analyzed at the laboratory facility of the University of Brescia. Manganese measurements in blood were performed by Zeeman graphite furnace atomic absorption spectrometry (Varian SpectrAA) in the Industrial Hygiene laboratory at the University of Brescia, Italy, using the methods previously reported in the first round of the recruitment and afterwards by magnetic sector inductively coupled mass spectrometry (Thermo Element XR ICP-MS) with rhodium and thallium as internal standards (Apostoli et al, 2000; Lucas et al, 2015). …”

Manganese in teeth and neurobehavior: Sex-specific windows of susceptibility

“…Located in northern Italy, this study was designed to investigate associations between Mn exposure from anthropogenic emissions and neurodevelopmental outcomes. Details of the study have been described elsewhere (Lucas et al 2015; Lucchini et al 2012b, 2012a). Briefly, PHIME participants include children ages 10–14 years residing in three geographically distinct, but demographically similar, regions in the Province of Brescia, Italy: Bagnolo Mella (BM), an area with currently active ferro-manganese industry that has been in operation since 1970; Valcamonica (VC), where ferro-manganese plants were operating for approximately a century until 2001; and Garda Lake (GL), a tourist area with no history of ferroalloy industry.…”