SPARK: Studies of occupational exposure to particles and cognitive health

Research problem and specific questionsParticles present in urban air have been found to have a detrimental effect on cognitive health.

However, despite workers experiencing significantly higher exposure levels, evidence regarding the association between occupational particle exposure and cognitive health remains sparse and is focused on a limited number of particle types. In addition, neuropathological insight into the association is lacking.

We will investigate a broad spectrum of occupational particle exposures and the continuum of cognitive health, addressing key confounding factors.

Research questions: What is the magnitude of the association between occupational particle exposure and risk of mild cognitive impairment and dementia? Are factors existing earlier in life confounding variables in this association?

How does particle exposure correlate with brain structure and function?Data and methodWe will use four complementary datasets: (1) A register-based cohort of about 5.6 million workers in Sweden 1985-2013, with data on occupational title, socioeconomic factors (parental occupation, education, income etc.), and diagnoses to minimise selection issues; (2) A subgroup of men (n=427,574) in the first cohort conscripted for military service during 1969-1990, with additional information on earlier-life cognitive ability and cardiorespiratory fitness to address important confounding; (3-4) two population-based cohorts (n=500 and 42,806, respectively) with brain MRI data to provide neuropathological evidence.

Occupational exposure to 10 categories (44 types) of particles is assessed using job-exposure matrices for all four datasets, and self-reported exposures are also available in cohorts 3 and 4.Societal relevance and utilisationThis collaborative research effort will address a considerable knowledge gap regarding occupational exposure to various particles, brain changes and cognitive dysfunction.

Our results may have significant implications for risk assessment, primary prevention, and promoting healthy aging and health equity.Plan for project realisationThe research group involved in the project is multidisciplinary, and the complementary expertise of the team members will guarantee a broad perspective considering occupational, geriatric, and environmental epidemiology, psychology, and public health, as well as adequate methodological, management, and impact-generating competence.

The budget covers salaries and register data updates.