This report augments guidelines published in 1990 for investigating clusters of health events (CDC. Guidelines for investigating clusters of health events. MMWR 1990;39[No. RR-11]). The 1990 Guidelines considered any noninfectious disease cluster, injuries, birth defects, and previously unrecognized syndromes or illnesses. These new guidelines focus on cancer clusters. State and local health departments can use these guidelines to develop a systematic approach to responding to community concerns regarding cancer clusters. The guidelines are intended to apply to situations in which a health department responds to an inquiry about a suspected cancer cluster in a residential or community setting only. Occupational or medical treatment-related clusters are not included in this report. Since 1990, many improvements have occurred in data resources, investigative techniques, and analytic/statistical methods, and much has been learned from both large- and small-scale cancer cluster investigations. These improvements and lessons have informed these updated guidelines. These guidelines utilize a four-step approach (initial response, assessment, major feasibility study, and etiologic investigation) as a tool for managing a reported cluster. Even if a cancer cluster is identified, there is no guarantee that a common cause or an environmental contaminant will be implicated. Identification of a common cause or an implicated contaminant might be an expected outcome for the concerned community. Therefore, during all parts of an inquiry, responders should be transparent, communicate clearly, and explain their decisions to the community.

Public health surveillance and epidemiology are the foundations for disease prevention because they provide the factual basis from which agencies can set priorities, plan programs, and take actions to protect the public's health. Surveillance for noninfectious diseases associated with exposure to agents in the environment like lead and pesticides has been a function of state health departments for more than 3 decades, but many state programs do not have adequate funding or staff for this function. Following the efforts to identify core public health epidemiology functions in chronic diseases, injury, and occupational health and safety, a workgroup of public health environmental epidemiologists operating within the organizational structure of the Council of State and Territorial Epidemiologists has defined the essential core functions of noninfectious disease environmental epidemiology that should be present in every state health department and additional functions of a comprehensive program. These functions are described in terms of the "10 Essential Environmental Public Health Services" and their associated performance standards. Application of these consensus core and expanded functions should help state and large metropolitan health departments allocate resources and prioritize activities of their environmental epidemiologists, thus improving the delivery of environmental health services to the public.

The Agency for Toxic Substances and | Disease Registry (ATSDR) determines | public health implications associated with | hazardous waste sites and other environmental releases. Since its inception, ATSDR | has continued to improve its approach to | evaluating public health hazards in light of | evolving science. For example, in response | to concerns about the clarity, meaning, and | understandability of the fi ve conclusion | categories outlined in its Public Health Assessment Guidance Manual (www.atsdr.cdc. | gov/HAC/PHAmanual/index.html), ATSDR | established an ad hoc work group to evaluate and recommend changes to the categories based on health and risk communication science. | All site-specifi c public health assessment | reports must include a statement that assigns a hazard conclusion category to the | site, a time period for exposure (e.g., past, | current, or future), or an exposure pathway, | as appropriate. This statement refl ects one | of the following: that the site does not pose | a public health hazard, that the site poses | a public health hazard, or that data are insuffi cient to determine whether any public | health hazard exists. The language used to | convey these categories, however, was diffi cult for community members and lay audiences to understand because it was not written clearly.

BACKGROUND: In 2007, a synthetic turf recreational field in Newark, New Jersey, was closed because lead was found in synthetic turf fibers and in surface dust at concentrations exceeding hazard criteria. Consequently, public health professionals across the country began testing synthetic turf to determine whether it represented a lead hazard. Currently, no standardized methods exist to test for lead in synthetic turf or to assess lead hazards. OBJECTIVES: Our objectives were to increase awareness of potential lead exposure from synthetic turf by presenting data showing elevated lead in fibers and turf-derived dust; identify risk assessment uncertainties; recommend that federal and/or state agencies determine appropriate methodologies for assessing lead in synthetic turf; and recommend an interim standardized approach for sampling, interpreting results, and taking health-protective actions. DISCUSSION: Data collected from recreational fields and child care centers indicate lead in synthetic turf fibers and dust at concentrations exceeding the Consumer Product Safety Improvement Act of 2008 statutory lead limit of 300 mg/kg for consumer products intended for use by children, and the U.S. Environmental Protection Agency's lead-dust hazard standard of 40 microg/ft2 for floors. CONCLUSIONS: Synthetic turf can deteriorate to form dust containing lead at levels that may pose a risk to children. Given elevated lead levels in turf and dust on recreational fields and in child care settings, it is imperative that a consistent, nationwide approach for sampling, assessment, and action be developed. In the absence of a standardized approach, we offer an interim approach to assess potential lead hazards when evaluating synthetic turf. EDITOR'S SUMMARY: A recreational field in Newark, New Jersey, was closed in 2007 because lead concentrations found in synthetic turf fibers and in surface dust exceeded hazard criteria. Consequently, public health professionals across the country began testing synthetic turf to determine whether it represented a lead hazard. Data collected from recreational fields and child care centers indicated lead in synthetic turf fibers and dust at concentrations that exceed the Consumer Product Safety Improvement Act of 2008 statutory lead limit of 300 mg/kg for consumer products intended for use by children and the U.S. Environmental Protection Agency's lead-dust hazard standard of 40 microg/ft2 for floors. The authors conclude that synthetic turf can deteriorate to form dust containing lead at levels that may pose a risk to children. Currently, no standardized methods exist to test for lead in synthetic turf or to assess lead. Ulirsch et al. (p. 1345) summarize data on lead in fibers and turf-derived dust and discuss risk assessment uncertainties. They also note the need for regulatory agencies to develop standardized methods for assessing lead in synthetic turf and recommend an interim approach for sampling, interpreting results, and taking health-protective actions.