Toxins in kids’ mattresses and bedding raise health concerns, study shows

Sleeping up to 18 hours a day, young children may unknowingly inhale a cocktail of harmful chemicals from their beds. Canadian researchers call for urgent regulation of mattresses and household items.

Study: Young Children’s Exposure to Chemicals of Concern in Their Sleeping Environment: An In-Home Study. Image Credit: LeManna / Shutterstock

In a recent article published in Environmental Science & Technology Letters, researchers measured the levels of potentially harmful chemicals in the mattresses, bedroom air, and sleeping microenvironments (SMEs) of children in Canada. Their findings indicate that mattresses may be a source of specific chemicals and that SME air contains higher concentrations than bedroom air. Based on these findings, the researchers highlighted the need for stricter chemical regulations and practical steps to reduce exposure.

Background

Behaviors such as mouthing objects, a higher surface area of skin relative to body weight, and higher breathing rates make children more vulnerable to environmental contaminants like semi-volatile organic compounds (SVOCs). Some organophosphate esters (OPEs) and ortho-phthalates (PAEs) have been implicated in hormonal disruptions and childhood asthma.

Young children, including infants, may sleep up to 18 hours a day, often in SMEs, defined as the body heat zone, surrounding air, bedding, and mattress. These SMEs may contain biological contaminants, volatile organic compounds (VOCs), and SVOCs. For example, the foam and outer layers of mattresses may emit ultraviolet (UV) filters, flame retardants, and plasticizers.

Though Canadian flammability regulations for mattresses do not require potentially harmful additives, they still contain PAEs and phosphate-based or brominated flame retardants. As these additives are not chemically bound, they may migrate into the air, bedding, dust, and even skin, increasing children’s potential exposure. The study also notes that previous research found that some new mattresses for children exceeded regulatory limits for certain SVOCs, despite European, American, and Canadian regulations, although this current study assessed environmental levels rather than direct regulatory exceedances. The paper also highlights that UV-328, one of the UV-filters measured, was recently listed as a Persistent Organic Pollutant (POP) under the Stockholm Convention, underscoring its global regulatory concern.

About the Study

The research team investigated levels of SVOCs in the bedroom air and SMEs in young children’s homes, focusing specifically on UV filters, OPEs, and PAEs. They tested the hypothesis that mattresses are a major source of SVOCs.

Between 2022 and 2023, 21 parents with 25 children between the ages of six months and four years were recruited from middle- to high-income homes in Ottawa and Toronto. The authors note that this socioeconomic focus may limit generalization to lower-income settings, where exposures can be higher. The children’s rooms were equipped with samplers that were deployed for seven days; a mattress sampler was used to isolate emissions from the mattress, an SME sample was placed under the sheet to quantify bedding emissions in the air around the child, and a room air sampler was suspended to sample air in the bedroom.

Chemical analysis of the samples included chromatography-mass spectrometry (GC-MS) to analyze levels of 51 SVOCs, including 14 UV filters, 29 OPEs, and 8 PAEs. Differences in the concentrations were then assessed using statistical methods such as Spearman’s rank testing and Mann-Whitney U-tests.

The study also notes limitations, including the relatively short passive sampling period (seven days), possible differences in sampler uptake rates due to airflow variations, and a modest sample size. These factors may affect the precision of exposure estimates.

Findings

The study assessed SVOCs in children’s bedrooms using three types of passive samplers placed in mattresses and SMEs and suspended in the room’s air. In air samplers, 28 SVOCs were detected, with the highest detection frequencies and concentrations observed for tris(chloropropyl phosphate) (TCPP), diethyl phthalate (DEP), methyl salicylate, and benzophenone (BP).

SME samplers detected 31 SVOCs, with the highest levels of tris(2-butoxyethyl)phosphate (TBOEP), DEP, phenyl salicylate, and BP, while mattress samplers detected 30 SVOCs, notably Di-n-butyl phthalate (DnBP), TCPP, phenyl salicylate (P-SAL), and BP-3.

Compared to other studies, SVOC air concentrations in children’s bedrooms were generally lower, though some compounds, particularly BP and diisobutyl phthalate (DiBP), were higher than levels measured in controlled office settings with new mattresses.

SVOC concentrations were generally higher in SME samplers than in room air samplers, indicating greater exposure in the sleeping environment. DEP and BP were significantly higher in room air, suggesting additional sources beyond bedding and mattresses. The study emphasizes that SVOCs in indoor environments can become “well-mixed” over time due to their physicochemical properties, making it challenging to attribute exposures to a single primary source without targeted product testing.

A comparison of SVOC levels between mattresses and SME samplers showed that mattresses were likely sources of certain SVOCs (namely TCPP and PAEs, but excluding DEP). TBOEP levels were higher in SME samplers, indicating bedding and textiles as potential sources.

Correlations showed that SVOC concentrations were influenced by room features and mattress age. For instance, older mattresses correlated with higher di-2-ethylhexyl phthalate (DEHP) and benzyl butyl phthalate (BzBP), while UV filters were linked to carpets, wall paint, and textile furnishings.

Use of personal care products was associated with higher levels of salicylates. However, the study found no significant correlation between DEP concentrations and reported use of personal care products. Collectively, multiple bedroom items, especially textiles and foam-based products, contributed to children’s exposure to SVOCs. The study also notes that mattress protectors, often used as waterproof barriers, may contain additional chemicals of concern, such as per- and polyfluoroalkyl substances (PFAS), which could further contribute to children’s chemical exposures in the sleeping environment.

Conclusions

This study confirms that children are significantly exposed to SVOCs in their sleeping environments, with many compounds originating from mattresses, bedding, and room furnishings. Given children’s extended time spent sleeping and their heightened vulnerability, these findings are concerning.

Harmful SVOCs like tris(2-chloroethyl) phosphate (TCEP), DnBP, and DEHP – some already regulated in children’s products – highlight the need for stricter, more comprehensive regulations. The authors emphasize that regulatory efforts must address not only toys and a limited set of products, but also broader product categories such as mattresses and textiles. They also note that there can be a significant time lag between the passage of new regulations and observed reductions in household exposures, underscoring the need for timely implementation and public awareness. The inclusion of substances like UV-328 in global treaties, as well as emerging concerns about PFAS in child sleep products, further demonstrate the urgency for a coordinated regulatory response.

To reduce exposure, the study recommends minimizing bedding items, frequently washing textiles, and avoiding products like mattress protectors that may contain additional chemicals. Frequent laundering of bedding and children’s clothing can help reduce SVOC accumulation, but parents should also be mindful that some textiles themselves may be sources. Manufacturers and retailers must ensure compliance with safety regulations, while policymakers should expedite regulatory updates.

Ultimately, protecting children from harmful chemical exposures requires greater focus on their sleeping environment and better enforcement of evidence-based policies.