This blog post is part of a biomonitoring series.
In 2011, CDC’s National Environmental Public Health Tracking Program formed a Biomonitoring Task Force, composed of grantees from the agency’s Tracking Network. Members of the new task force were asked to find out what biomonitoring data exists in states and, where possible, to add it to the national tracking network’s data portal.
“There is an important and growing partnership between CDC-funded state tracking programs and laboratories interested in biomonitoring,” said Jean Johnson, PhD, supervisor, environmental epidemiology unit, and director, environmental public health tracking and biomonitoring program, at the Minnesota Department of Health. “CDC tracking programs bring the environmental epidemiology piece that is a critical resource for state laboratories interested in population-based biomonitoring.”
Identifying Environmental Health Surveillance as a Priority
The Tracking Network was established in response to a 2000 Pew Environmental Health Commission Report, which revealed a fragmented surveillance system. Information gaps and data silos prevented scientists from connecting data on environmental exposures with chronic disease data.
“The consensus was that, if we created surveillance for environmental health, we would do a much better job connecting environmental hazards and exposures to Americans’ health,” said Johnson.
In 2002, CDC funded the new surveillance program that is typically referred to as the Tracking Network. Sixteen states were brought on board to systemically collect, analyze and disseminate environmental public health data. Since that time the network has grown to 23 states plus New York City and several academic partners. The participating states pull the data together by identifying and exploring existing data sources. Epidemiologists analyze the data for trends and spatial patterns. The academic partners then take a research angle, examining the data for connections.
There are approximately 15 content areas tracked in each state, including air quality, drinking water, chronic disease from cancer registries, heart disease, and carbon monoxide poisoning. In most states, children’s blood lead levels are the only biomonitoring data that have been tracked systematically, although federal support for blood lead surveillance in the states was recently cut.
All of this data is available to the public on web portals. “That’s an important part of tracking too because it’s not just states that use the data,” said Johnson. “Universities, advocate organizations, community and local public health folks: if it’s public data, it’s accessible to everyone who wants to use it.”
The participating states all agree to track certain things so that the network is supplied with nationally consistent data and measures. Teams from the states first identify what a consistent measure is, and then provide the data to CDC and post it to the public portals. Yet states are also free to add supplemental information that may be particularly relevant to their region.
“This program has really helped build significant environmental epidemiology capacity in state health departments,” said Johnson.
Taking Environmental Health Surveillance a Step Further by Adding Biomonitoring Data
In 2011, network participants decided to investigate whether any of the biomonitoring work conducted in the states was consistent enough to allow for national tracking of the data. The Biomonitoring Task Force was established, and it developed and sent a survey to the 23 states in the tracking program. The survey asked the states to review the past 10 years of available biomonitoring data to identify what analytes were tested, how, on what populations and with what kind of funding. Essentially the network was searching for consistencies that would make a particular chemical (in populations) trackable on a national platform.
In the survey, biomonitoring testing was split into five categories:
1) Mandatory report data: some states require hospitals or clinics to report poisonings or chemical exposures
2) Population-based survey: surveillance to measure spatial or temporal differences in population exposure or to evaluate the efficacy of public health actions to reduce exposure (for example, any state programs similar to NHANES)
3) Targeted public health investigation: in response to community health concerns about contamination or a disease cluster (drinking water contamination)
4) Rapid response: in response to an emergency situation, such as a chemical emergency in a school or community
5) Support of academic research project: providing laboratory support to academic institutions
Overall the results (see slide image below) reveal that there is very limited consistency among state biomonitoring programs, which would make it difficult to enter the data into a national tracking program. Very few of the studies use probability-based population sampling methods, meaning that researchers cannot generalize the results outside of the tested group.
Johnson pointed out that each state likely has more biomonitoring data than was identified in the survey since a lot of work never gets reported or published in peer-reviewed journals.
The survey results made it clear that the state tracking grantees want to build their biomonitoring programs. However, there is a significant lack of sustained resources to support state biomonitoring work.
The next activity on the task force’s agenda is to write a white paper to describe the current limitations posed by the existing data, and recommend strategies to help create consistent data across the country.
In the years to come, as states develop their biomonitoring programs, it will be important to work with the tracking network so that this valuable data is accessible and useful to anyone who needs it.
Without biomonitoring, public health practitioners face challenges in understanding whether environmental contaminants are actually being absorbed into people’s bodies. Given improvements in technology, the capabilities and expertise that exist in public health laboratories, and the increasing demand from the public for more information about chemical exposures, biomonitoring is poised to become an integral component of public health practice.
To learn more about biomonitoring, check out some of APHL’s Biomonitoring Resources:
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