Key Findings of America’s Children and the Environment
These Key Findings summarize the most important findings from each of the America’s Children and the Environment indicators. Note that the years for which data are available vary across the indicators.
For many of the America’s Children and the Environment indicators, evidence of relationships between environmental exposures and children’s health continues to evolve. Just because an indicator is included in this report, it doesn’t necessarily mean there is a known relationship between exposures to a specific environmental contaminant and impacts on children’s health.
On this page:
Environments and Contaminants
Criteria Air Pollutants
Updated 2023
- From 1999 to 2021, the proportion of children living in counties with measured pollutant concentrations above the levels of one or more national ambient air quality standards decreased from 76% to 59%.
- From 1999 to 2021, the percentage of children living in counties with measured ozone concentrations above the 8-hour ozone standard for at least one day during the year decreased from 66% to 51%.
- From 1999–2021, the percentage of children living in counties with measured PM2.5 concentrations above the level of the current 24-hour PM2.5 standard at least once per year decreased from 55% in 1999 to 34% in 2021. Over the same years, the percentage of children living in counties with a measured concentration above the level of the current PM2.5 annual standard decreased from 37% in 1999 to 8% in 2021.
- Based on categories from EPA’s Air Quality Index, the percentage of children’s days that were designated as having “unhealthy” air quality decreased from 10% in 1999 to 4% in 2021. The percentage of children’s days with “good” air quality increased from 38% in 1999 to 53% in 2021. The percentage of children’s days with “moderate” air quality decreased from 24% in 1999 to 22% in 2021.
- In 2021, considering only days with monitoring data, good air quality days were highest for White children at 73% and lowest for Hispanic children at 58%.
Hazardous Air Pollutants
- In 2014, nearly all children (99.8%) lived in census tracts in which hazardous air pollutant (HAP) concentrations combined to exceed the 1-in-100,000 cancer risk benchmark. In the same year, 0.3 percent of children lived in census tracts in which HAPs combined to exceed the 1-in-10,000 cancer risk benchmark, and 0.1 percent of children lived in census tracts in which at least one HAP exceeded the benchmark for health effects other than cancer.
Indoor Environments
- In 2010, 6% of children ages 0 to 6 years lived in homes where someone smoked regularly, compared with 27% in 1994.
- In 2005-2006, 15% of children ages 0 to 5 years lived in homes with either an interior lead dust hazard or an interior deteriorated lead-based paint hazard, compared with 22% in 1998-1999.
Drinking Water Contaminants
Updated 2023
- The estimated percentage of children served by community drinking water systems that did not meet all applicable health-based standards declined from 20% in 1993 to about 5% in 2001. Since 2002, this percentage has fluctuated between 5% and 12%, and was 7% in 2021.
- Between 1993 and 2021, the estimated percentage of children served by community drinking water systems that had at least one monitoring and reporting violation fluctuated between about 10% and 23% and was 11% in 2021.
Chemicals in Food
- In 1999, 81% of sampled apples had detectable organophosphate pesticide residues; in 2016, 6% had detectable residues. In 2000, 10% of sampled carrots had detectable organophosphate pesticide residues; in 2014, 5% had detectable residues. In 2000, 21% of sampled grapes had detectable organophosphate pesticide residues; in 2016, less than 1% had detectable residues. In 1998, 37% of sampled tomatoes had detectable organophosphate pesticide residues; in 2016, 2% had detectable residues.
Contaminated Lands
Updated 2023
- Approximately 3.7% of all children in the United States lived within one mile of contaminated lands (Corrective Action or Superfund site) that may not have had all human health protective measures in place as of 2021.
- In 2021, approximately 36% of all children living within one mile of contaminated lands (Corrective Action or Superfund site) that may not have had all human health protective measures in place were Hispanic, while 26% of children in the United States as a whole are Hispanic.
Biomonitoring
Lead
Updated 2023
- The median concentration of lead in the blood of children between the ages of 1 and 5 years dropped from 15 micrograms per deciliter (µg/dL) in 1976-1980 to 0.6 µg/dL in 2017-March 2020, a decrease of 96%. At the 95th percentile, blood lead levels dropped from 29 µg/dL in 1976- 1980 to 2.1 µg/dL in 2017-March 2020, a decrease of 93%.
- In 2017-March 2020, median blood lead levels by age group were highest among young children ages 1 and 2 years (0.7 µg/dL) and decreased by age group through ages 16 to 17 years (0.4 µg/dL). The 95th percentile blood lead levels were also highest among young children ages 1 and 2 years (2.4 µg/dL) and decreased by age group through ages 16 and 17 years (1.1 µg/dL).
- The median blood lead level in Black non-Hispanic children ages 1 to 5 years in 2015-March 2020 was 0.8 µg/dL, higher than the level of 0.6 µg/dL in White non-Hispanic children, 0.7 µg/dL in Mexican-American children, and 0.6 µg/dL in children of “All Other Races/Ethnicities.”
Mercury
- The median concentration of total mercury in the blood of women ages 16 to 49 years decreased from 0.9 micrograms per liter (µg/L) in 1999-2000 to 0.6 µg/L in 2017-2018.
- Among women in the 95th percentile of exposure, the concentration of total mercury in blood decreased from 7.4 µg/L in 1999-2000 to 3.7 µg/L in 2001-2002. From 2001-2002 to 2017-2018, the 95th percentile of total blood mercury remained between 3.7 and 4.5 µg/L.
Cotinine
Updated 2023
- The median level of cotinine (a marker of exposure to environmental tobacco smoke) measured in blood serum of nonsmoking children ages 3 to 17 years decreased by 92% from 1988-1991 to 2017- 2020. Cotinine values at the 95th percentile decreased by 34% from 1988-1991 to 2017-2020.
- In 2015–2020, median concentrations of cotinine in blood for nonsmoking children were approximately 0.10 ng/mL for Black non-Hispanic children, 0.03 ng/mL for White non-Hispanic children, 0.02 ng/mL for Mexican-American children, and 0.02 ng/mL for children of “All Other Races/Ethnicities.”
- In 2015–2020, the median concentration of cotinine in blood serum for nonsmoking children living below the poverty level (0.07 ng/mL) was about 4 times the median for nonsmoking children living at or above the poverty level (0.02 ng/mL).
- In 2015-2020, cotinine values at the 95th percentile were more than four times higher for nonsmoking women living below the poverty level (5.0 ng/mL) than for nonsmoking women living at or above the poverty level (1.1 ng/mL).
Perfluorochemicals (PFCs)
- Between 1999-2000 and 2017-2018, median blood serum levels of perfluorooctane sulfonic acid (PFOS) in women ages 16 to 49 years declined from 24 ng/mL to 3 ng/mL, and median blood serum levels of perfluorooctanoic acid (PFOA) declined from 5 ng/mL to 1 ng/mL; median levels of perfluorononanoic acid (PFNA) increased from 0.5 ng/mL to 1.0 ng/mL between 1999-2000 and 2009-2010, and then decreased to 0.3 ng/mL in 2017-2018. Median levels of perfluorohexane sulfonic acid (PFHxS) decreased from 1.3 ng/mL to 0.6 ng/mL between 1999-2000 and 2017-2018.
Polychlorinated Biphenyls (PCBs)
- In 2001-2004, the median level of polychlorinated biphenyls (PCBs), summing together four selected PCBs, in blood serum of women ages 16 to 49 years was 30 nanograms per gram (ng/g) lipid. Data are not yet available for comparing these PCB levels over time.
Polybrominated Diphenyl Ethers (PBDEs)
- The median concentration of polybrominated diphenyl ethers (PBDEs) in blood serum of women ages 16 to 49 years was 44 ng/g lipid in 2003-2004. Data are not yet available for comparing these PBDE levels over time.
Phthalates
Updated 2023
- In general, the phthalate metabolites included in this indicator dataset have decreased over time for the years 1999-2018.
- For the years 2015-2018, Black non-Hispanic women of child-bearing age and Black children had higher median concentrations of phthalate metabolites in urine compared with any other races/ethnicity.
- For the years 2015-2018, women and children living below poverty level had higher concentrations of phthalate metabolites in their urine compared with women and children living at or above poverty level.
- For the years 2015-2018, children ages 6 to 10 years had higher median levels of phthalate metabolites in their urine compared to adolescents ages 16-17 years.
Bisphenol A (BPA)
- From 2003-2004 to 2015-2016, the median concentration of bisphenol A (BPA) in urine among women ages 16 to 49 years generally decreased from 3 µg/L to 1 µg/L. From 2003-2004 to 2015-2016, the concentration of BPA in urine at the 95th percentile varied between 6 µg/L and 16 µg/L, and was 6 µg/L in 2015-2016.
- Among children ages 6 to 17 years the median concentration of BPA in urine decreased from 4 µg/L in 2003-2004 to 1 µg/L in 2015-2016. The concentration of BPA in urine at the 95th percentile decreased from 16 µg/L in 2003-2004 to 7 µg/L in 2015-2016.
Perchlorate
- From 2001-2002 to 2007-2008, the median level of perchlorate in urine among women ages 16 to 49 years was 3 µg/L with little variation over time. From 2007-2008 to 2013-2014, the median level decreased from 3.4 to 2.6 µg/L. From 2001-2002 to 2007-2008, the 95th percentile perchlorate levels among women ages 16 to 49 years varied between 13 and 17 µg/L. From 2007-2008 to 2013-2014, the 95th percentile level decreased from 17 to 10 µg/L.
Health
Respiratory Diseases
Updated 2023
- The proportion of children reported to currently have asthma increased from 8.7% in 2001 to 9.4% in 2010, and then decreased to 6.5% in 2021.
- In 2018-2021, the percentages of Black non-Hispanic children and children of “All Other Races/Ethnicities” reported to currently have asthma, 12.3% and 8.6% respectively, were greater than for Hispanic children (6.4%), White non-Hispanic children (5.6%), and Asian non-Hispanic children (3.4%).
- The rate of emergency room visits for asthma was 114 visits per 10,000 children in 1996, varied between 47 and 128 visits per 10,000 children from 1996 to 2020, and was 47 visits per 10,000 children in 2020.
- The rate of emergency room visits for 2017-2020 for asthma and all other respiratory causes was almost 3 times higher for Black non-Hispanic children compared to White non-Hispanic children, and 1.5 times higher for Black non-Hispanic children compared to Hispanic children.
Childhood Cancer
- The age-adjusted annual incidence of childhood cancer increased from 1992-2018. The incidence ranged from 154 to 161 cases per million children between 1992 and 1994 and from 186 to 193 cases per million children between 2016 and 2018.
- Childhood cancer mortality decreased from 33 deaths per million children in 1992 to 22 deaths per million children in 2018.
- Leukemia was the most common cancer diagnosis for children from 2017-2018, representing 30% of total cancer cases. Incidence of acute lymphoblastic (lymphocytic) leukemia was 30 cases per million in 1993-1994 and 35 cases per million in 2017-2018. The rate of acute myeloid (myelogenous) leukemia was 7.2 cases per million in 1993-1994 and 9.3 cases per million in 2017-2018.
Neurodevelopmental Disorders
Updated 2023
- From 1997 to 2021, the proportion of children ages 5 to 17 years reported to have ever been diagnosed with attention-deficit/hyperactivity disorder (ADHD) increased from 6.3% in 1997 to 10.8% in 2021.
- In 2021, 7.9% of children ages 5 to 17 years have been diagnosed with a learning disability. There was little change in this percentage between 1997 and 2021.
- The percentage of children ages 5 to 17 years reported to have ever been diagnosed with autism rose from 0.1% in 1997 to 1.2% in 2013. Between 2014 and 2021, the rates of reported autism ranged from 2.3% to 3.7%.
- For 2018–2021, the prevalence of autism was higher for children living below the poverty level (4.2%) than those living at or above the poverty level (2.8%).
- In 2021, 1.8% of children ages 5 to 17 years were reported to have been diagnosed with intellectual disability. This percentage fluctuated between 0.6% and 0.9% from 1997 to 2010 and was between 1.0% and 2.4% from 2011 to 2021.
Obesity
- Between 1976-1980 and 2015-2016, the percentage of children identified as obese showed an increasing trend. In 1976-1980, 5% of children ages 2 to 17 years were obese. This percentage reached a high of 18% in 2015-2016. Between 1999-2000 and 2015-2016, the percentage of children identified as obese remained between 15% and 18%.
- In 2013-2016, 14% of White non-Hispanic children were obese, compared with 24% of Mexican-American children, 21% of Black non-Hispanic children, and 19% of children of “All Other Races/Ethnicities.”
Adverse Birth Outcomes
- The rate of preterm birth increased from 11.0% in 1993 to 12.8% in 2006.
- The rate of preterm birth declined from 10.4% in 2007 to 9.6% in 2015, and then increased to 10.2% in 2019. Values from 2007 to the present are not comparable to those for earlier years due to a change in the measure for estimating gestational age.
- The rate of term low birth weight stayed relatively constant between 1993 and 2006, ranging between 2.5% and 2.7%.
- The rate of term low birth weight increased from 2.4% in 2007 to 2.5% in 2019. Values from 2007 to the present are not comparable to those for earlier years due to a change in the measure for estimating gestational age.