These Key Findings summarize the most important findings from each of the America’s Children and the Environment indicators. Please see the body of the report for background information on the 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
• Biomonitoring
• Health

Environments and Contaminants

Criteria Air Pollutants

• From 1999 to 2017, 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 62%. This includes both concentrations above the level of any current short-term standard at least once during the year as well as average concentrations above the level of any current long-term standards.
• In 2017, 7% of children lived in counties with measured ozone concentrations above the level of the 8-hour ozone standard on more than 25 days. An additional 9% of children lived in counties with measured concentrations above the level of the ozone standard between 11 and 25 days, and 18% of children lived in counties where concentrations were above the level of the standard between 4 and 10 days.
• In 2017, 1% of children lived in counties with measured fine particle (PM2.5) concentrations above the level of the 24-hour PM2.5 standard on more than 25 days. One percent of children lived in counties with measured concentrations above the level of this standard between 11 and 25 days, and an additional 8% of children lived in counties with measured concentrations above the level of the 24-hour PM2.5 standard between 8 and 10 days.
• 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 11% in 1999 to 4% in 2017. The percentage of children’s days with “good” air quality increased from 36% in 1999 to 54% in 2017. The percentage of children’s days with “moderate” air quality decreased from 25% in 1999 to 19% in 2017.

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

• The estimated percentage of children served by community drinking water systems that did not meet all applicable health-based standards declined from 18% in 1993 to about 5% in 2001. Since 2002, this percentage has fluctuated between 5% and 11%, and was 6% in 2017.
• Between 1993 and 2017, the estimated percentage of children served by community water systems that had at least one monitoring and reporting violation fluctuated between about 10% and 21%, and was 12% in 2017.

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

• As of 2018, approximately 2% of all children in the United States lived within one mile of a Corrective Action or Superfund site that may not have had all human health protective measures in place.
• Approximately 15% of all children living within one mile of a Corrective Action or Superfund site that may not have had all human health protective measures in place were Black, while 14% of children in the United States as a whole are Black.

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Biomonitoring

Lead

• 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 0.7 µg/dL in 2015-2016, a decrease of 95%. At the 95th percentile, blood lead levels dropped from 29 µg/dL in 1976-1980 to 2.8 µg/dL in 2015-2016, a decrease of 90%.
• The median blood lead level in Black non-Hispanic children ages 1 to 5 years in 2013-2016 was 0.9 µg/dL, higher than the level of 0.7 µg/dL in White non-Hispanic children, Mexican-American children, and 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 0.7 µg/L in 2015-2016.
• 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 2015-2016, the 95th percentile of total blood mercury remained between 3.7 and 4.5 µg/L.

Cotinine

• 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 dropped from 0.25 nanograms per milliliter (ng/mL) in 1988-1991 (ages 4 to 17 years) to 0.03 ng/mL in 2015-2016, a decrease of 88%. Cotinine values at the 95th percentile decreased by 50% from 1988-1991 to 2015-2016.
• The median level of cotinine measured in blood serum of nonsmoking women of child-bearing age dropped from 0.19 ng/mL in 1988-1991 to 0.02 ng/mL in 2015-2016, a decrease of 89%. Cotinine values at the 95th percentile decreased by 54% from 1988-1991 to 2015-2016.

Perfluorochemicals (PFCs)

• Between 1999-2000 and 2015-2016, 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 0.4 ng/mL in 2015-2016. Median levels of perfluorohexane sulfonic acid (PFHxS) decreased from 1.4 ng/mL to 0.6 ng/mL between 2003-2004 and 2015-2016.

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

• From 2001-2002 to 2007-2008, the median level of di-2-ethylhexyl phthalate (DEHP) metabolites in urine of women ages 16 to 49 years varied between 41 µg/L and 51 µg/L, and was 51 µg/L in 2007-2008. The median level of DEHP metabolites decreased to 14 µg/L in 2013-2014. From 1999-2000 to 2007-2008, the median level of dibutyl phthalate (DBP) metabolites in women ages 16 to 49 years varied between 27 µg/L and 36 µg/L, and was 36 µg/L in 2007-2008. The median level of DBP metabolites decreased to 20 µg/L in 2013-2014. From 1999-2000 to 2007-2008, the median level of butyl benzyl phthalate (BBzP) metabolite in women ages 16 to 49 years varied between 10 µg/L and 14 µg/L, and was 12 µg/L in 2007-2008. The median level of BBzP metabolite decreased to 6 µg/L in 2013-2014
• From 2001-2002 to 2007-2008, the median level of DEHP metabolites in urine of children ages 6 to 17 years varied between 45 µg/L and 62 µg/L, and was 45 µg/L in 2007-2008. From 2007-2008 to 2013-2014, the median level of DEHP metabolites in urine of children ages 6 to 17 years decreased to 16 µg/L. From 1999-2000 to 2007-2008, the median level of DBP metabolites in children ages 6 to 17 years varied between 36 µg/L and 42 µg/L, and was 41 µg/L in 2007-2008. From 2007-2008 to 2013-2014, the median level of DBP metabolites in urine of children ages 6 to 17 years decreased to 25 µg/L. The median level of BBzP metabolite in children ages 6 to 17 years decreased from 25 µg/L in 1999-2000 to 8 µg/L in 2013-2014.

Bisphenol A (BPA)

• From 2003-2004 to 2011-2012, 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 2011-2012, the concentration of BPA in urine at the 95th percentile varied between 10 µg/L and 16 µg/L, and was 11 µg/L in 2011-2012.
• Among children ages 6 to 17 years the median concentration of BPA in urine decreased from 4 µg/L in 2003-2004 to 2 µg/L in 2011-2012. The concentration of BPA in urine at the 95th percentile decreased from 16 µg/L in 2003-2004 to 9 µg/L in 2011-2012.

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.

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Health

Respiratory Diseases

• The proportion of children reported to currently have asthma increased from 8.7% in 2001 to 9.4% in 2010, and then decreased to 8.4% in 2017.
• In 2014-2017, the percentages of Black non-Hispanic children and children of “All Other Races” reported to currently have asthma, 13.8% and 11.7% respectively, were greater than for Hispanic children (7.7%), White non-Hispanic children (7.4%), and Asian non-Hispanic children (4.7%).
• The rate of emergency room visits for asthma was 114 visits per 10,000 children in 1996, varied between 80 and 128 visits per 10,000 children from 1996 to 2015, and was 74 visits per 10,000 children in 2016. Between 1996 and 2010, hospitalizations for asthma and all other respiratory causes decreased from 90 hospitalizations per 10,000 children to 64 hospitalizations per 10,000 children.

Childhood Cancer

• The age-adjusted annual incidence of cancer increased from 1992-2016. The incidence ranged from 154 to 161 cases per million children between 1992 and 1994 and from 185 to 191 cases per million children between 2014 and 2016.
• Childhood cancer mortality decreased from 33 deaths per million children in 1992 to 23 deaths per million children in 2016.
• Leukemia was the most common cancer diagnosis for children from 2013-2016, representing 26% of total cancer cases. Incidence of acute lymphoblastic (lymphocytic) leukemia was 33 cases per million in 1997-2000 and 37 cases per million in 2013-2016. The rate of acute myeloid (myelogenous) leukemia was 8.2 cases per million in 1997-2000 and 8.3 cases per million in 2013-2016.

Neurodevelopmental Disorders

• From 1997 to 2017, 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% to 10.7%.
• In 2017, 8.8% of children ages 5 to 17 years had ever been diagnosed with a learning disability. There was little change in this percentage between 1997 and 2017.
• 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 2017, the rates of reported autism ranged from 2.3% to 2.8%. The higher reported percentages in these years might be due in part to the recent broadening of the definition of autism used in the survey question.
• In 2017, 1.0% of children ages 5 to 17 years were reported to have ever been diagnosed with intellectual disability (mental retardation). This percentage fluctuated between 0.6% and 0.9% from 1997 to 2010, and was between 1.0% and 1.5% from 2011 to 2017. The higher reported percentages in 2011 to 2017 might be due in part to the revision of the survey question wording.

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 2014, and was 9.9% in 2017. 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 2.6% in 2017. 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.

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