by Kim Smiley
Lead poisoning has once again hit the news with scary headlines such as “Blood Lead Levels High In 535,000 Kids In The USA” and “Despite Big Progress, Many Kids Have High Lead Levels in Blood“. But what do these articles actually mean in context? What does “many kids” refer to and how alarmed should we be?
A tool like a Cause Map, a visual method for performing a root cause analysis, can be useful to analyze issues like this one. The first step in the Cause Mapping process is to define the problem and that alone can help clarify an issue. Part of defining the problem is to determine which overall organizational goals are being impacted by the problem. In this example, it becomes clear that there are really two different, but related goals that need to be considered. The most basic goal is the safety goal. The safety goal is being impacted because children are still being negatively impacted by exposure to lead in the United States, despite decades of work to dramatically reduce lead in the environment. The second issue is that 2.6% of children in the US have blood lead levels (BLLs) higher than the levels set by the Center for Disease and Control (CDC), an impact to the regulatory goal.
It’s clear why exposure to lead remains a concern. Ingestion of lead is dangerous, especially to small children. High levels of lead in the body can have severe and immediate consequences such as coma, convulsions and even death. Lower levels of lead have been shown to cause lower IQs, behavior issues, hearing problems and a number of problems in organs in the body. Problems with lead exposure are well known and the use of lead has been dramatically reduced. Use of lead in household paints, one of the most common sources of ingested lead, was banned in 1978. However, paint is still one of the primary sources of lead contamination because many children live in houses built before 1978. Paint chips containing lead can still be an issue, especially if an older house has loose paint or is undergoing a renovation. Use of lead in gasoline, a common source of soil contamination, was phased out by the end of the 1980s.
The second issue of concern is that 2.6% of children have blood lead levels above the limit set by the CDC. What does this mean? If this problem is hitting headlines, are things getting worse? One important piece of data is that the CDC lowered the limit for young children in 2012 to 5 µg/dL from 10 µg/dL. Why was the limit lowered? The limit was lowered because no amount of lead has been determined to be safe for young children and less lead is always better. The new limit of 5 µg/dL was based on lead levels in the 2.5% of children with the highest levels. It was a way to target the children most at risk and it marked a shift towards a more prevention-based approach.
Is it okay that 2.6% of children still have blood lead levels above the target? Of course not. Is there still work to do in preventing lead exposure? Many people believe there is. But the alarming headlines may not tell the whole story. Here are some other facts that help put the issue of lead exposure in historical context: an estimated 88% of children aged 1 to 5 had blood lead levels at or above 10 mcg/dL from 1976 to 1980; from 1991-1994 it was 4.4% , from 1999-2002 it was 1.6% and it dropped to 0.8% in 2007-2010. Lead exposure is a still an issue, but it’s an issue that has been drastically improved.
To view a Cause Map of this issue, click on “Download PDF” above. For more information, click here to visit the CDC’s information page about lead.