Sources of Lead Exposure for Full Cases, Fiscal Year 2019 to 2020
- In FY 2019-2020, there were 329 new children meeting full case criteria, however, only 248 children (75%) received full case management services (both PHN visit and on-site environmental investigation), mainly due to COVID. Of these 248 children, 82.3 percent were less than 6 years old, 52 percent were male, and 44.8 percent were Hispanic.
- Major sources of lead exposure differed significantly by race/ethnicity.
- Housing-related sources (paint, dust, soil, water) of lead were the main exposure sources among non-Hispanic Black children.
- Non-housing sources of lead were the main exposure sources among non-Hispanic Asian children or non-Hispanic White children with Afghan origin.
- Unlike non-Hispanic children, both housing and non-housing sources of lead were commonly identified among Hispanic children.
- Lead found in food, spice and drinks, cosmetic and spiritual products, pottery/utensils, and take-home/occupational were commonly identified non-housing exposures in racially and ethnically diverse populations.
The Childhood Lead Poisoning Prevention Branch (CLPPB) analyzed sources of lead exposure for children who were newly identified as full cases in FY 2019-2020 and consented to full case management, including environmental services. Every child meeting the full case definition is eligible to receive both public health nurse (PHN) case management services and an environmental investigation (EI) by an environmental professional (EP). During an EI, the EP assesses the child's environment for lead exposure sources in paint, dust, soil, and water, and documents the results. The PHN performs a visit to the family often at the same time as the EI, which includes collecting information to evaluate and coordinate the necessary services. Non-housing items may also be collected and sent for laboratory analysis. “Non-housing sources" are sources of lead exposure other than housing-related paint, dust, soil, and water. In FY 2019-2020, due to the COVID-19 pandemic, an initial EI started as a remote exposure assessment by a structured questionnaire on the phone. The PHN visit and REA findings were reviewed and discussed at CLPPB, and EIs were done if the visit could not be deferred.
When housing-related lead sources are identified, EPs work with property owners to ensure the properties are remediated expediently. Properties remain open to follow up until the property passes a clearance inspection. A successful clearance inspection includes, at a minimum, a visual inspection to verify all required work was completed properly, as well as collection and analysis of dust wipe samples. For full cases where paint, dust, soil, and/or water were identified as a source, CLPPB reviewed whether the sources of lead exposure were removed, remediated, or abated.
In this analysis, only children with blood lead levels (BLLs) meeting the full case criteria during FY 2019-2020 who received full case management, including an on-site environmental investigation, were included. As of July 1, 2016, children meet full case criteria with either a single venous blood lead level (BLL) at or above 14.5 micrograms per deciliter (µg/dL) or persistent levels at or above 9.5 µg/dL. Data on blood lead results were gathered from the Response and Surveillance System for Childhood Lead Exposures (RASSCLE) database.
Exposure assessment data came from two sources:
(1) EPs collected samples and information about housing-related sources of lead exposure, such as paint, dust, soil, and water as well as non-housing items. The lead content in these samples (except water) were measured by X-Ray Fluorescence (XRF) screening by EPs, as well as quantitatively in the environmental health laboratories.
(2) PHNs collected information about non-housing sources of lead exposure, such as the child's behavior, food, products used for cooking, and alternative medicines, using a structured questionnaire during the PHN visit.
Race/ethnicity data were also collected by the PHN during the visit. CLPPB collects race/ethnicity data in a two-question format similar to the Federal Office of Management and Budget (OMB) race and Hispanic ethnicity categorizations. Race/ethnicity data collection was based on a parent's report of the child's identity with the ability to select all applicable races and one applicable ethnicity. Race category choices in the lead follow-up forms were:
- Native American/Alaskan
- Black/African American
- Pacific Islander
- Decline to state.
If a parent identified the child as Asian or Pacific Islander, they were asked to further select from more detailed categories of Asian and Pacific Islander races. If the parent identified the child as “Other" race, they were asked to specify. Ethnic background categories were:
- Not Hispanic/Spanish/Latino
- Yes, North American (Mexican, Mexican American)
- Yes, Central American
- Yes, South American
- Yes, other Spanish/Hispanic/Latino.
Answers to 'Country of birth' question were also used to help race/ethnicity categorization for data analysis when needed. CLPPB followed the California Department of Public Health vital statistics reporting categories for race/ethnicity for the data analysis: Mutually exclusive race/ethnicity categories were:
- Non-Hispanic Asian
- Non-Hispanic Black
- Non-Hispanic Hawaiian/Pacific islander
- Hispanic (single race)
- Multi-race (any ethnicity)
- Non-Hispanic Native American/Alaskan
- Non-Hispanic Other
- Non-Hispanic White
- Declined or Unknown.
If a parent identified the child's race only as 'Other' and chose any of the 'Yes' Hispanic ethnicity options, then the child was categorized as Hispanic (single race). If multiple race categories were checked, then regardless of Hispanic ethnicity status, the child was categorized as Multi‑race (any ethnicity). For simplicity, Hispanic (single race) children will be described hereafter as Hispanic children, and non-Hispanic children will be described by their race category alone (e.g., non-Hispanic Asian children will be referred to as Asian children). In FY 2019-2020, there were 47 children with Afghan origin. They mostly identified themselves as 'White', 'Asian' or 'Other' and specified as Afghan. In this analysis, Afghan and all other Middle Eastern/North African children were categorized as 'White' following OMB guidelines. Of the 65 White children, 47 (72.3%) were Afghan, and sources of lead exposure differed by Afghan origin. For this reason, the White race category was stratified as Afghan and non-Afghan. Similarly, the Asian race category was stratified as Asian Indian and other Asian.
CLPPB reviewed EI documentation to identify housing-related sources associated with full cases. For each investigation, CLPPB measured lead 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. Paint, dust, and soil were categorized as lead exposure sources based on regulatory levels found in Title 17, California Code of Regulations (CCR), beginning with Section 35001. The Los Angeles County local health jurisdiction also categorized housing-related sources with their own regulatory statutes (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). EPs identified lead housing-related sources 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 (Table 1).