Chemicals behind global kidney failure outbreaks found in US pregnant women

No worries, it's melamine

Melamine – a chemical found in certain types of plastic dishware that the World Health Organization recently classified as “possibly carcinogenic” – made global news for causing outbreaks of kidney failure and deaths in pets in 2004 (Korea) and 2007 (U.S.) and later in children in 2008 (China). This was because manufacturers had added melamine to fake the protein content of pet food and baby formula. While this generated attention to regulate melamine in food, the question is whether people are still being exposed to melamine and similar chemicals like cyanuric acid.

While most people aren’t familiar with these chemicals, they are found in a wide variety of products, including flooring, hair dyes, plastics, and pesticides. They are also produced in extremely high quantities – more than 100 million pounds a year in the U.S. alone – and are not routinely tested for toxicity, so we wanted to better understand whether and how people are being exposed. Prior studies explored exposure to these chemicals in Asian countries and workers in the U.S., but no one had looked at how vulnerable populations such as pregnant people and children were affected.

U.S. pregnant women are widely exposed to melamine, cyanuric acid, and aromatic amines

Our new study found that melamine and cyanuric acid, along with four aromatic amines, were found in nearly all pregnant women from various racial and ethnic backgrounds (34% white; 40% Latina; 20% Black; 4% Asian; 3% from other or multiple racial groups). In this study, we used new methods to measure 45 chemicals in urine samples collected from 171 women from California, Georgia, Illinois, New Hampshire, New York, and Puerto Rico who are part of the National Institutes of Health Environmental influences on Child Health Outcomes (ECHO) Program.

Alarmingly, levels of these chemicals were higher among women of color. We found similar exposure disparities in an earlier study of more than 100 other chemicals, pointing to environmental justice concerns related to exposure sources. Levels were also higher among those with greater tobacco exposure.

These findings call for further research to better understand why exposures still exist and why levels of many chemicals are higher in certain racial/ethnic groups.

Why are these chemicals in our bodies and what should we do?

Cyanuric acid is similar to melamine and is used as a disinfectant, plastic stabilizer, and in swimming pools. Aromatic amines can be found in hair coloring, mascara, tattoo ink, paints, tobacco smoke, and diesel exhaust. Our daily encounters with these products through the air, contaminated food, food packaging, household dust, water, plastics, products that contain dyes/pigments, and more, can increase levels of these chemicals in our bodies.

While individuals may try and avoid contact with products that contain these chemicals, it is nearly impossible given their many uses. Instead, population-wide policies are needed to restrict the use of these chemicals and regularly monitor their levels in the general public to ensure that population exposures are kept at a safe level. We can all take action to move the needle by increasing awareness, participating in advocacy activities locally or internationally, or conducting additional research that can serve as scientific evidence for policy-making.

To this end, and to better understand possible health problems due to these exposures, we are currently expanding the number of study participants who are pregnant to >1700 to assess whether higher exposure to these chemicals during pregnancy is related to health problems in children.

Read more about
Aromatic amines:

About the authors

Giehae Choi, PhD is a Postdoctoral Fellow at the Johns Hopkins University Department of Environmental Health and Engineering in the Buckley Research Group. She uses epidemiologic training received at UNC to conduct research aimed at improving children’s environmental health.


Jessie P. Buckley, PhD is an Associate Professor at the Johns Hopkins University Department of Environmental Health and Engineering. She studies early life environmental chemical exposures to inform policies targeted at improving children’s health.