What was studied?
This original research article, titled “Environmental Tin Exposure in a Nationally Representative Sample of U.S. Adults and Children: the National Health and Nutrition Examination Survey 2011–2014,” conducted a detailed investigation into environmental tin exposure among the general U.S. population. The research utilized data from the National Health and Nutrition Examination Survey (NHANES) for the years 2011–2014, employing inductively coupled plasma mass spectrometry (ICP-MS) to measure tin concentrations in urine samples. The focus was on analyzing how demographic (age, gender, race/ethnicity), socioeconomic (income, education), and lifestyle factors (physical activity, smoking, alcohol use, BMI) are associated with variations in urinary tin levels. Findings from this study are particularly relevant to the heavy metal certification industry, as they illuminate the prevalence, distribution, and modifiable determinants of tin exposure across the U.S. population, thereby informing regulatory monitoring and risk mitigation strategies within heavy metal certification programs.
Who was studied?
The study population comprised 5,163 individuals, including 3,522 adults (aged 20 years and older) and 1,641 children (aged 6–19 years), who participated in the NHANES 2011–2014 cycles and had available urinary tin measurements. The sample included diverse demographic and socioeconomic groups, reflecting the broader U.S. population’s variability in age, gender, race/ethnicity, and income. For adults, further stratification was done according to age (20–39, 40–59, ≥60 years), gender, race/ethnicity (non-Hispanic white, non-Hispanic black, Hispanic, other), education, income to poverty ratio, smoking status, alcohol consumption, physical activity, and BMI. Children were similarly stratified by age (6–11, 12–19 years), gender, race/ethnicity, income, and BMI. This comprehensive approach enabled robust analysis of exposure determinants essential for heavy metal certification programs.
Most important findings
| Critical Points | Details |
|---|---|
| Ubiquity of Exposure | Urinary tin was detected in 87.05% of adults and 91.29% of children, confirming nearly ubiquitous exposure across the U.S. population. |
| Tin Levels by Age | Older adults (≥60 years) had nearly double the median urinary tin levels compared to younger adults (20–39 years). In children, those aged 6–11 had twice the tin levels of adolescents (12–19). |
| Median/Geometric Means | Adult median and geometric mean urinary tin: 0.42 µg/L and 0.49 µg/L, respectively. Children: 0.60 µg/L (median) and 0.66 µg/L (geometric mean). |
| Demographic Associations | Age, gender (females had higher creatinine-adjusted tin), race/ethnicity (non-Hispanic blacks had higher levels), and income were significantly related to urinary tin in both adults and children. |
| Socioeconomic Factors | Lower household income was associated with higher urinary tin levels in both adults and children. |
| Lifestyle Factors | Greater physical activity in adults correlated with lower urinary tin levels. Alcohol consumption was associated with lower tin, but not significantly in multivariate analysis. BMI and education showed limited association. |
| No Significant Dietary Link | Prior studies and this analysis did not find a robust association between canned food consumption and urinary tin levels, despite diet being a presumed exposure route. |
| Methodological Note | ICP-MS measured total urinary tin but did not differentiate between inorganic and more toxic organotin compounds. |
| International Comparison | U.S. population tin levels were broadly comparable to those in Europe and Japan, though variations exist. |
| Exposure Disparities | Children, non-Hispanic blacks, and lower-income groups are at elevated risk, highlighting the need for targeted public health and regulatory interventions. |
Key implications
For heavy metal certification programs, these findings underscore the need to address widespread, population-level exposure to tin, especially among children, older adults, non-Hispanic blacks, and lower-income groups. Certification standards should consider demographic and socioeconomic disparities and refine risk assessment and mitigation strategies. The inability to distinguish between inorganic and organic tin forms in biomonitoring highlights a critical need for more precise analytical methods to inform regulation and certification efforts.
Citation
Lehmler HJ, Gadogbe M, Liu B, Bao W. Environmental Tin Exposure in a Nationally Representative Sample of U.S. Adults and Children: the National Health and Nutrition Examination Survey 2011–2014. Environ Pollut. 2018 Sep;240:599–606. doi:10.1016/j.envpol.2018.05.019.
Heavy metals are high-density elements that accumulate in the body and environment, disrupting biological processes. Lead, cadmium, arsenic, mercury, nickel, tin, aluminum, and chromium are of greatest concern due to persistence, bioaccumulation, and health risks, making them central to the HMTC program’s safety standards.