THE PUBLIC HEALTH scourges of centuries past, like cholera or typhoid fever, were often linked to overcrowded and substandard housing, made worse by lack of sewers and other basic sanitation. Pity those people in the 18th and 19th centuries, faced not only with infectious and fatal diseases, but little information about their cause or their cure.

In this modern age, we still live in an age of unenlightenment, at least when it comes to lead paint. We've known about the dangers of lead paint for almost a century, and research on the neurological disorders from children eating lead paint goes back to the 1940s. Lead in paint was finally banned in the 1970s.

We should be looking back to the lead paint past as long gone, a remnant of another age. Yet, according to a report this week in the Daily News and Inquirer, here in Philadelphia, it's a plague that is still with us.

Although serious headway has been made from 2006, when a staggering number of children in the city registered high levels of lead, the report found that 8 percent of the city's children still register a high level. The Centers for Disease Control and Prevention says public health officials should intervene when a child's blood-lead level reaches five micrograms per deciliter; 8 percent of Philadelphia's children have a level of 5 or higher. The city doesn't intervene until levels reach 10.

Chalk this problem up to a combination of factors: an old city with an old housing stock (houses built before 1978 are the likeliest culprits for lead) and lax enforcement of regulations, leading to landlords who are empowered to take advantage of low-income families.

It's important to note that lead paint itself can be in any ZIP code. But the ZIP codes that are home to low-income people are especially vulnerable, with housing that is unlikely to have been upgraded.

That means we are all impacted by the ravages of lead paint. For one thing, lead-poisoned children exhibit behavioral and other problems, and their intellectual development is arrested. Imagine the demands that places on our education system, to say nothing of the public health budget. From a purely economic standpoint, this costs all of us.

Of course, the impact is beyond economic: It's a human rights issue. We are poisoning children who are already disadvantaged, making it all the more harder for them to have a future, assuring them only that the cycle of poverty, disease and disadvantage continues. The net effect is that the moment these children are born, we are signing a slow-death certificate.

Granted, lead paint is a complicated problem: Fixing lead-painted apartments can be expensive, so too many landlords ignore the problem. The city's lax enforcement of rental units and landlords excerbate the problem, and while there are many city departments that have jurisdiction, including Public Health and Licenses and Inspection, better coordination among all the parties would be more effective.

Earlier in the decade, a federal program funded a huge decline of the problem, but that money dried up. Unlike other more intractable problems, remediating or abating lead paint is a fix-once-and-done solution. And the fix can have long-reaching impact on improving lives. The Kenney administration has a great opportunity here to figure out how to marshal its resources so that our most vulnerable citizens can stop being poisoned.