Table 1.

Summary of epidemiological studies on particulate matter (PM) and associated metals and their effects on brain health.

Study	Study Design	Inhalation Exposure	Results
Haynes et al., 2018	Expansion of Communities Actively Researching Exposure (CARES) cohort (n = 106; East Liverpool Ohio, US)	Mn	Exposure negatively associated with Full Scale IQ measurements among children
Haynes et al., 2015	Expansion of CARES cohort (n = 404; East Liverpool Ohio, US)	Mn	Exposure negatively associated with Full Scale IQ measurements among children
Menezes-Filho et al., 2018	Cross-sectional study (n = 225; Simões Filho, Bahia, Brazil)	Mn and Pb	Exposure associated with intellectual deficiencies (IQ)
Pesch et al., 2017	Second follow up survey of Heinz Nixdorf Recall Study (HNRS) cohort (n = 1232; Germany)	Mn	Exposure associated with impaired dexterity
Palzes et al., 2019	Cross-sectional (n = 48; Zarcero County, Costa Rica)	Mn-associated fungicide	Exposure not associated with changes in working memory
Pujol et al., 2016	BREATHE Project cohort (n = 2836; Barcelona, Spain)	Cu	Exposure associated with impaired motor performance and altered basal ganglia in children
Lubczyńska et al., 2020	Generation R cohort (n = 2954; Rotterdam, Netherlands)	Various sizes of PM (including PM2.5) and metal constituents (including Si and Zn)	PM2.5 exposure associated with decrease in children’s fractional anisotropy Si exposure associated with increase in mean diffusivity Zn exposure associated with increase in mean diffusivity
Liu et al., 2018	Single-blind randomized cross-over trial (n = 53; Toronto, Canada)	Urban coarse ambient PM (>PM10); Concentrated ambient PM (PM0.1); Related metals (Al, Ba)	Ba exposure associated with increase in ubiquitin C-terminal hydrolase L1 Al exposure associated with increased urinary neural marker vanillylmandelic acid