Sources of Lead Exposure for Full Cases Fiscal Years (FY) 2015 to 2016 and 2016 to 2017 

Extracted from the 2020 Biennial Report (PDF). Please refer to References section of the 2020 Biennial Report for in-text citations made on this page.

Media of paint, dust, and soil were categorized as lead exposure sources based on regulatory levels found in Title 17, California Code of Regulations (CCR), Sections 35001 and following. Local Jurisdictions with local regulatory levels categorized lead hazards per their statute (e.g., Los Angeles County Code Section 11.28.010). Water results were categorized as exposure sources based on the United States Environmental Protection Agency (US EPA) action level (40 Code of Federal Regulations [CFR] Section 141.80). Lastly, environmental professionals (EPs) identified lead hazards based on direct known exposure to lead-poisoned children, including media below current regulatory standards but found to be significant based on a child's specific behavior and activity. All of these items were recorded as exposure sources at the levels found in Appendix G.

Any environmental investigation (EI) property found to have a lead hazard source must have it removed, remediated, or abated. Those properties remain open to EP follow-up until the completion of a clearance inspection.  Passing a clearance inspection requires visual confirmation that lead hazards have been corrected and furthermore quantifiable evidence through dust wipes that no lead-contaminated dust remains. CDPH reviewed documentation from the corresponding EI properties in FYs 2015-16 and 2016-17 to assess how many had passed clearance inspection.

There may be a number of potential lead exposure sources identified for a child with BLLs meeting full case criteria. When multiple potential exposure sources are identified, the exact contribution of each source to the child's initial BLL cannot be verified. It is common for children to have multiple potential sources of lead exposure, and exposures may be cumulative over time.

It should be noted that the age of the housing may reflect the age of the neighborhood and the years of lead deposition in the soil from petroleum and other air lead emitters. Hundreds of thousands of metric tons of lead remain in California soil and act as a "reservoir" for dust and soil contamination in and around homes and communities.¹⁷ The levels of lead in soil, paint, and house dust are all highly inter-correlated with each other and with the age of the house.

Distribution of Environmental Sources

In 2018 and 2019, CLPPB undertook an analysis of the sources of exposure to lead for children who were newly identified as full cases in FY 2015-16 and FY 2016-17 who consented to full case management and environmental investigation (EI) services. This combines the public health nurse's (PHN's) information about case behavior and possible non-housing sources of lead exposure as well as EI findings regarding paint, dust, soil, and water. Complete source information is not yet available for FY 2017-18, since identifying all lead exposure sources associated with a case may take an extended period of time. (While not available when the 2020 report was published, FY 2017 to 2018 data can now be found on CLPPB's Sources of Lead Exposure for Full Cases, Fiscal Year 2017 to 2018 web page). Families sometimes do not share all potential exposure sources immediately and new information may be identified as case management continues. If the child's BLL is not decreasing as expected, case management may require multiple follow-up visits and investigation of secondary locations.

For the analysis of full cases for FY 2015-16, CDPH included 188 children whose full case-making BLL result was received by CDPH from July 1, 2015, to June 30, 2016.

On July 1, 2016, CDPH lowered the BLL criteria used to define a full case, resulting in an increased number of children who received case management and EI services. For the analysis of full cases for FY 2016-17, sources of exposure were assessed in 570 children whose full case-making BLL result was received between July 1, 2016 and June 30, 2017.

CDPH reviewed EI documentation from FY 2015-16 and FY 2016-17 to identify environmental sources associated with full cases. For each investigation, CDPH recorded ranges of lead found in deteriorated paint, dust, and bare soil. Results of first and second draw water samples from kitchen sinks were also recorded, as well as water draws from other frequent drinking water locations.

Of the 188 full cases in the analysis for FY2015-2016, depending on which "actionable" levels of paint, dust, soil and water were used (Appendix H), cases for which no sources of lead exposure were found ranged from 14 children (7.5 percent) to 38 children (20.2 percent). The majority of the remaining children had exposure from paint, dust, or soil. Depending on which "actionable" levels of paint, dust, soil and water were used, the proportion of cases whose homes displayed any actionable paint, dust, soil or water ranged from a low of 58 percent, to a high of 82 percent. The distribution of environmental lead hazards from FY 2015-16 can be found in Appendix G.

Of the 570 full cases in the analysis for FY2016-17, depending on which "actionable" levels of paint, dust, soil and water were used, cases for which no sources of lead exposure were found ranged from 79 children (13.9 percent) to 142 children (24.9 percent). Depending on which "actionable" levels of paint, dust, soil and water were used, the proportion of cases whose homes displayed any actionable paint, dust, soil or water ranged from a low of 46 percent, to a high of 68 percent. The scientific validity of the regulatory "actionable" levels that influence the above‑mentioned proportions have not been well established. The distribution of environmental lead hazards from FY 2016-17 is described below in Figure 7. For both FY 2015-16 and FY 2016-17, paint was the main environmental hazard identified among full cases followed by soil, dust, and water. 

Figure 7. Total Occurrences¹ of Environmental Lead Hazards² at Current Regulatory Levels Identified Among Full Cases, Fiscal Year 2016-17

Notes:

1 A child may have more than one type of environmental lead hazard and therefore, the total occurrences of environmental lead hazards will be greater than the number of children identified with a lead hazard.

2 Environmental lead hazards include:

• A paint hazard signifies the presence of deteriorated lead-based paint, tested at the state regulatory level of ≥ 1.0 mg/cm². In addition, full cases were attributed to paint hazards at local regulatory levels: Los Angeles at ≥ 0.7 mg/cm². (17 CCR Sections 35022, 35033, 35037; Los Angeles County Code Section 11.28.010)
• Dust is considered a hazard when it is lead-contaminated at ≥ 40 mcg/ft² for interior floor surfaces, ≥ 250 mcg/ft² for interior horizontal surfaces, and ≥ 400 mcg/ft2 for exterior floor and exterior horizontal surfaces. (17 CCR Sections 35035, 35037)
• Soil is considered a hazard when it is lead-contaminated at ≥ 400 ppm in children's play areas.
• Water levels are categorized by an action level; according to the US EPA, ≥ 0.015 mg/L is above the action level (40 CFR Section141.80). Four water samples above the action level were found to be potential exposure sources to lead. Follow-up steps were taken to mitigate these potential exposures and subsequent re-sampling showed non-detect levels of lead. Two additional water samples were above the action level due to sampling errors. The first error was due to the water valve being closed at the bottom of the sink. The second error was due to the water main being shut off to the residence. These errors are not indicative of potential exposure sources. Subsequent testing under normal conditions at both residences, of water standing for > 6 hours, measured non-detect lead levels.

Removal, Remediation, or Abatement of identified Sources

Of the 188 full cases in our analysis for FY 2015-2016, 87 had an environmental lead hazard identified at current regulatory levels. Of the 87 children who were identified as having a lead hazard exposure, 70 properties (80.46 percent) had their hazards removed, remediated, or abated while 17 properties (19.54 percent) are still in the process of having lead hazards removed, remediated, or abated.

Of the 570 full cases in our analysis for FY 2016-17, 196 had an environmental lead hazard identified at current regulatory levels. Of the 196 children who were identified as having a lead hazard exposure, 168 properties (85.71 percent) had their hazards removed, remediated, or abated while 28 properties (14.29 percent) are still in the process of having lead hazards removed, remediated, or abated.

CDPH discussed each pending property with local jurisdiction EPs to verify that removal, remediation, or abatement of hazards is still underway. There are many reasons why properties are still pending. For example:

• The work at some homes was completed expediently, but a clearance inspection has not yet passed due to the difficulty of cleaning very small dust particles from rough, porous, or carpeted surfaces.
• Properties have changed hands over a short period of time, which has slowed the remediation process.
• Property owner neglect or refusal to complete the work has complicated the remediation process.
• Some properties have an extensive number of hazards throughout the home, requiring extra time to properly develop abatement plans, acquire permits, and hire certified personnel to complete the work.

Distribution of Non-Housing Sources

"Non-housing sources" are sources of lead exposure other than property‑associated paint, dust, soil, and water. Information about the child's possible exposure to these sources was obtained through interviews with family members and the child's primary care provider by EPs and PHNs providing case management services to the family. Quantitative information about possible sources of lead in the child's environment included results available from X-Ray Fluorescence (XRF) screening performed by EPs, and results from laboratory analysis of non-housing items.

Information reported to CDPH about housing and non-housing sources was reviewed by a CDPH physician to determine whether each potential source was a probable source of lead exposure for the child. Determination of whether a potential source was a probable source of lead exposure for a child was based on quantitative XRF and/or laboratory results; results of testing the item with a qualitative method (chemical test kit lead swab); amount, timing and length of the child's access to the item; and whether there is a significant history of demonstrated high lead content for a given potential source. In addition, the physician considered information about whether removal of the item from the child's environment was associated with a decline in BLL.

In FY 2015-16 and 2016-17, non-housing sources were found to be associated with 408 of the 758 full cases. The majority of the full cases with non-housing lead exposure sources also had property-associated environmental sources of lead. Table 10 shows a list of non-housing sources identified in FY 2015-16 (Appendix G) and 2016-17 (Figure 8).

For FY2015-16 and FY2016/17, the main non-housing exposure identified was take-home/occupational exposure and cosmetics/religious substances. However, the third non-housing exposure identified was pottery/utensils for FY2015-16 and food/drink/spices for FY2016-17.

Table 10. Non-housing Sources Identified, Fiscal Year 2015-16 and 2016-17

*Additional sources that have been identified in other time periods

Notes:

1 A child may have more than one type of non-housing exposure and therefore the total occurrences of non-housing exposures hazards will be greater than the number of children identified with a non-housing hazard (n = 313).

Notes:

Notes:

1 A child may have more than one type of non-housing exposure and therefore the total occurrences of non-housing exposures hazards will be greater than the number of children identified with a non-housing hazard (n = 95).

Appendix H: Lower Actionable Levels

Lower Actionable Levels Considered for Exposure Sources from Paint, Dust, Soil and Water for the 188 Full Cases in Fiscal Year 2015-16 (with Environmental Lead Hazards, Defined In Appendix G, at the Current Actionable Levels).