TITLE: Lead is harmful at any dose; push is on to lower lead limits for Americans
SENTENCE 1: According to economist Werner Troesken, who led the new review, the latest data still shows that children exposed to lead at today's levels score lower on intelligence tests and suffer more low-level health problems during old age compared to non-exposed children.Based on these findings, the CDC decided to act on the recommendations of a federal advisory committee and lower the "level of concern" for lead exposure from 10 micrograms per deciliter (mcg/dL) -- children with levels of lead exposure as low as 1.3 mcg/dL showed symptoms of lead poisoning -- to 5 mcg/dL.But if lead has mostly been phased out of commercial use, what is the source of all this lead exposure today?
SENTENCE 2: But during a recent evaluation, the agency determined that there really is no safe level of exposure to lead, and that the only way to ensure public safety is to continue lowering this threshold every four years until it eventually reaches zero.It was previously believed that only higher exposures to lead through lead paint, lead piping and leaded gasoline, all of which have been phased out of use, were a threat to human health.
SENTENCE 3: In the 1970s, anything over 30 micrograms per deciliter was the official CDC definition for elevated childhood levels; in 1985 it dropped to 25, and in 1991 it dropped to 10," writes Cristy Gelling for the"Last year, the CDC endorsed a recommendation to use a shifting definition that would be lowered every four years, stating it cannot pinpoint a particular level of lead that is 'safe.

Bias label: moderately
Annotator rationales:
If you claim that there is no safe level of lead exposure, then you risk presenting a specific scientific conclusion as absolute truth without acknowledging ongoing research or potential nuances in the scientific community's understanding.
If you present historical data without clarification of the factors that led to these changes over time, then you risks implying that these changes are driven solely by increased concern over health risks, without considering improvements in measurement technology or better understanding of lead exposure risks.
If this historical context is used to show that past beliefs about lead exposure were mistaken, then it risks implying that current levels of lead exposure, now often associated with environmental or industrial sources, are inherently dangerous without fully explaining how these new risks compare to past ones.
If you raise the question of where lead exposure is coming from despite its phase-out in commercial use, then you risk implying that the source of lead exposure is unclear or widespread, potentially contributing to confusion or concern about its presence in everyday environments without specifying the exact risks.