Prioritizing lead service line replacement (LSLR) projects by children's actual exposure

Exploring replacement priorities in the city of Malden, MA


The city of Malden, MA still has a large number of drinking water service lines which are made out of lead, either on the city side (under the street and sidewalk) or the private side (from under the sidewalk to the basement).

Lead exposure is hazardous to health, especially for children. Service lines made out of lead have the potential to expose inhabitants to lead toxicity. Because lead has disproportionately serious impacts on young children, the goal of this project is to explore the intersection of where the lead service lines are and where the city's children live.

According to The Boston Globe, as of 2016 "Malden is the community [in the Boston area] with the highest percentage of service lines made of lead; 47 percent of the city’s 11,682 service lines are lead, according to the Massachusetts Water Resource Authority’s best estimates."

Diagram of lead service lines between water main and house
Image from LSLR Collaborative.

According to Potash et al, "Exposure to lead has been found to be associated with premature birth and early neurological development issues such as edema, herniation, atrophy, and white-matter degeneration. Lead can cause vomiting; convulsions; paralysis; and, in high concentrations, death. Elevated blood lead levels are associated with lower IQs in children. A retrospective study by Mazumdar et al shows that, on average, a 1 µg/dL increase in blood-lead level is associated with a decrease of 1 IQ point among six-month-olds and 2 IQ points among 10 year olds."

In this tool, we'll look at which parcels in Malden have both lead service lines and children living in the home, and then add up the years of possible exposure at the level of a street segment (usually 1-2 city blocks, around the right size for a scheduled lead service line replacement project). To calculate years of exposure, we will assume that a child will live at a certain address until the age of 18. That means that a five year old child living at a parcel with a lead service line is assigned 13 exposure years (18 minus 5). This is not perfect, because the family could move to a different address or the service line could be replaced in that time.

For more information about the problem, the project, and the methodology, you can check out the about page. To see whether there is lead in your property or at a parcel where no children live, you can use the City's official GIS map. You should be aware that the number of recorded private service lines might not be fully accurate or updated, but the City will inspect your service line for free if you submit a request online here.

Here, we can experiment with the following question:

Replacing service lines on which street segments would provide the biggest return on investment reducing public health impact on vulnerable children?

Take me to the explorer tool →