Kidsdata.org provides data on California children and youth ages 0-20 who are administered a blood lead screening, by age group. Among children/youth screened in each age group, the number and percentage with blood lead levels (a) below 4.5 micrograms per deciliter (mcg/dL), (b) between 4.5 and 9.49 mcg/dL, and (c) at least 9.5 mcg/dL, are available at the state and county level.

Lead is a major environmental threat to children's health in the U.S. (1, 2). Childhood exposure to lead—usually through contaminated paint, dust, soil, or water—is linked to lifelong adverse effects on physical, neurological, cognitive, academic, and economic outcomes (1, 2). Children are especially vulnerable to toxic substances such as lead, as their bodies are fragile and still developing (1, 3). Young children are the most vulnerable and tend to come into the greatest contact with lead, through playing or crawling on the ground or through hand-mouth contact (1, 3). More than one third of homes in the U.S. contain lead-based paint, including nearly four million homes with young children (2). Some groups are at higher risk for lead exposure than others, particularly low-income, African American/black, and Latino/Hispanic children (1, 2, 4).

Preventing lead exposure before it occurs is essential, as no safe blood lead level in children has been identified (1, 5). The threshold at which the CDC recommends public health action be taken is 3.5 micrograms per deciliter (mcg/dL) (5). Lead exposure often goes undetected as it usually does not result in obvious symptoms, making effective screening and early intervention for exposed children critical (2, 5).

Estimates indicate that the economic burden of lead exposure in the U.S. is between $50 billion and $84 billion annually due to reduced productivity and costs related to health care, education, and incarceration (2, 4). In California alone, it is estimated that lead exposure costs $8-11 billion in lost earnings over the lifetimes of children born in a single year (4).

Blood lead screening results were reported for 368,813 California young people ages 0-20 tested in 2020—a drop of nearly 30% when compared with 2019 and almost 50% compared with 2010. Among those tested in 2020, 1.3% recorded a blood lead level (BLL) of at least 4.5 micrograms per deciliter (mcg/dL). This amounts to 4,930 children and youth statewide, the vast majority (3,950) under age 6, with levels at which the state requires direct public health responses including case management and follow-up. Across counties with data, the percentage of children ages 0-5 with BLLs at or above 4.5 mcg/dL ranged from less than 0.5% to more than 4% of those tested.

Lead poisoning—the most common environmental illness among California children—is a serious but entirely preventable public health issue (1). It can cause lifelong physical, neurological, cognitive, and behavioral problems, as well as lower academic achievement and earnings in adulthood (2, 3). Lead exposure is particularly harmful for young children, whose developing systems are especially vulnerable (1). Lead exposure may occur through paint, dust, soil, water, or other sources. No safe level of lead exposure has been identified (2). Experts agree that prevention is the best course of action, and although regulations and abatement efforts have helped reduce the prevalence of lead in the environment in recent decades, lead continues to pose a significant threat to U.S. children (3).

Public attention on lead poisoning has increased in recent years, with recognition of its continued harm to children's health and significant economic burden for society (3). Attention also has focused on inequities in lead exposure, with children of color and those in low-income communities facing the greatest risks (2, 3). California has enacted wide-ranging legislation to address these issues, but much work remains and lead risks are far from eliminated (2, 4).

Policy and practice options to prevent and address lead poisoning include:

• Continuing to enforce and strengthen policies focused on primary prevention of lead exposure, alongside those focused on remediating hazardous environments and identifying and caring for children who have been exposed (2, 4)
• Ensuring that government at all levels—federal, state, and local—has the capacity to effectively identify and respond to populations at risk; also, improving alignment of national, state, and local plans to control and eliminate lead hazards (5)
• Improving collaboration across sectors to ensure that all children affected by lead exposure are identified and receive early intervention services, such as through home-visiting programs; as part of this, administering blood lead screenings in accordance with federal and state regulations (2, 3, 6)
• Prioritizing prevention efforts in low-income communities and focusing broadly on multiple sources of lead and multiple environmental hazards in housing, communities, schools, and early childhood settings—e.g., by advancing strategic public-private partnerships among health, housing, education, and environmental sectors (2, 7)
• Promoting effective implementation of policies and guidelines for environmental health in schools and child care settings, as well as strengthening legislation and increasing funding to eliminate lead risks in these settings (4, 7)
• Improving private sector commitments to lead-free practices and compliance with regulations regarding residential renovations, repairs, and painting (3, 6, 7)
• Educating diverse audiences about the effects of lead exposure and how to prevent it; also, promoting training and assistance for professionals in multiple sectors regarding lead and other environmental health issues (6, 7)
• Supporting continued research on the connections between the environment and children's health, ways to improve state and local lead prevention and intervention efforts, and effective programs to improve outcomes for lead-exposed children (2, 6)