EPA Response to October 15, 2012 CTEC Letter on Blood Lead Action Level
The following is a letter from EPA Montana Office Superfund Branch Chief Joe Vranka, written in reply to a CTEC letter inquiring about the effect of Center for Disease Control (CDC) action levels regarding lead in children on Butte Superfund. Download the original CTEC letter using the link at the bottom of this post.
November 16, 2012
RE: EPA risk assessment and action level selection for lead contamination and the recent Center for Disease Control advisory on blood lead levels in children
Dear Dr. Ray:
This letter responds to your letter, on behalf of Citizen’s Technical Environmental Committee, to Mr. Henry Elsen of the U.S. Environmental Protection Agency (EPA) dated October 15, 2012, and an identical letter to Ms. Terri Hocking of the Butte Silver Bow County Health Department on the same date. Both letters asked about the status of EPA’s review of the Center for Disease Control (CDC) May 2012 updated advisory regarding children’s blood lead levels, and whether the revised CDC advisory would lead to a change in EPA’s risk based cleanup level for lead in the Butte Priority Soils operable unit (BPSOU) under the Superfund program for the BPSOU.
The May 2012 CDC advisory changes language used in CDC documents regarding blood lead levels so these documents no longer refer to a 10 micrograms per deciliter (ug/dL) blood lead level in children as a “level of concern.” The advisory instead notes that a 5 ug/dL blood lead level in children should be used as a reference value for blood lead levels in children for public health agencies addressing problems with blood lead levels. CDC has emphasized in its documents concerning the new advisory that this reference level should be used by physicians to identify individuals at risk from lead exposure.
EPA personnel involved with Superfund human health risk assessments and public health are not conducting a formal review of EPA policy in light of this CDC advisory, but have had informal, internal discussions about what the CDC advisory means in terms of Superfund cleanups, risk assessments, and action levels. EPA risk assessors believe the best way to address the issues raised in the CDC advisory is to emphasize the use of blood lead testing, lead-based paint abatement, and community health programs, as these programs address the most common sources of lead exposure for individual children. EPA does not plan to change its human health risk assessment methodology at this time, nor does it plan to change or revise prior human health risk assessments or risk management decisions, such as those done for the BPSOU.
The Residential Metals Abatement Program (RMAP) for BPSOU, which implements the lead action levels at the BPSOU, does include language concerning prioritization ‘of cleanup activities and other public health intervention activities, based on any reported blood lead level above 10 ug/dL. During the coming winter, EPA may seek changes to the RMAP that reflect the new CDC advisory reference value in that context. I believe this answers the issue marked as (1) in your October 15 letter.
In issue number (2) of your letter, you ask if the current lead action level for the BPSOU is sufficient to achieve the 5 ug/dL level, and you ask for assurances that the current action level for lead is protective of human health. EPA believes the current lead action level and response actions to implement this action level are protective of human health at the BPSOU. The Public Health Study, currently available in draft form for review and required by the RMAP itself (note: the draft Public Health Study Work Plan is available for download on the CTEC site here – CTEC is unaware of any completed Public Health Study conducted by EPA or its consultants), will review and evaluate the available RMAP data that have been collected to date in order to objectively document the efficacy of the RMAP and identify any areas where improvement to activities conducted via the RMAP may be needed to effectively identify and mitigate potentially harmful exposures to sources of lead, arsenic and mercury in the Butte community.
In issue number (3) of your letter, you ask if the method that Butte Silver Bow County currently uses to measure blood lead levels is adequate and precise enough to measure acceptable blood lead levels. Previous blood lead data studies conducted in Butte used methods with a detection limit of 1 ug/dL. The current Lead Care II method used by Butte Silver Bow County has a detection limit of 3.3 uh/dL. Thus, past and current measurement methods were and are adequate to measure blood lead levels at and below 5 ug/dL. Additionally, the blood lead measurement methods currently being used will be examined in the Public Health Study in terms of their ability to document the efficacy of the RMAP.
Thank you for this opportunity to respond to your questions. if you have any questions or require additional information, please contact Sara Sparks (406-782-7415), Nikia Greene (406-457- 5019) or Susan Griffin (303-312-6651).
Joseph Vranka, P.E.
Superfund Branch Chief