Magnetite particles, suspected to cause neurodegenerative problems, are generated as environmental pollutants from which of the following? 1. Brakes of motor vehicles 2. Engines of motor vehicles 3. Microwave stoves within homes 4. Power plants 5. Telephone lines Select the correct answer using the code given below.

Shows that vehicle emissions cause respiratory irritation and inflammation and that vehicle-derived air pollutants have documented health impacts.

A student could combine this with knowledge that inhaled particles can translocate to the brain to suspect health effects from metal-rich brake particles and seek studies measuring those particles and neurological outcomes.

Notes that particulate emissions (fly ash) can be 'oxide rich' and include oxides of iron — an example that iron oxides can occur as airborne particulate matter.

A student could use this as a precedent that iron oxides can exist in airborne particulates and then look for measurements identifying Fe3O4 specifically in traffic-related PM (e.g., roadside sampling near braking zones).

States that vehicles are a major source of ground-level pollution and particulate-laden smog forms from vehicle emissions.

Combine with the fact that brakes operate at road-vehicle interfaces where particles are generated to justify targeted sampling near roads to test for brake-origin magnetite particles.

Emphasises that motor vehicles inject large amounts of chemicals/particles into the atmosphere and these can be transported widely.

A student could infer that if brakes emit iron-containing particles, those could disperse from roads and be measured at varying distances to assess environmental release.

Describes regulatory focus (emission standards) on controlling vehicle emissions, implying that vehicle-generated pollutants are a recognized concern subject to monitoring and regulation.

One could check whether regulations/standards and monitoring programs include non-exhaust sources (e.g., brake wear) and iron-oxide particle measurements to evaluate the plausibility and extent of brake-derived magnetite pollution.