Or perhaps "systemic oppression" is being used to refer to all the little things that add up in aggregate. Perhaps lead levels contribute only a small amount.

Or perhaps "systemic oppression" is being used to refer to all the little things that add up in aggregate. Perhaps lead levels contribute only a small amount. But then also, micro-aggressions have a tiny affect. Testing bias might also be very small. Maybe less income also leads to being less likely to get glasses when you need them. Perhaps food deserts in minority communities leads to poor nutrition and poorer outcomes, but only a negligible amount. Then there are poorer, urban neighborhoods that might be loud at night causing children to not get quite enough sleep. And sure, you could blame a lot of this just on poverty in general, but then of course, you have to acknowledge our racist history that lead to so much less wealth in minority families. It goes on and on and pretty soon you have death by a thousand cuts and a phenomenon that is far too complex to explain in anything less than an entire encyclopedia so you sum it up with "systemic racism".