Exposure and Health Risk Assessment of Phthalates in House Dust among Schoolchildren in Phatthalung, Thailand

Nuttapong Leamun; Kraichat Tantrakarnapa; Orawan  Kaewboonchoo; Siriphat Intrakun

Authors

Nuttapong Leamun Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University and 2Department of Disease Control, Ministry of Public Health, Thailand, Email: nuttapong.lae@student.mahidol.ac.th
Kraichat Tantrakarnapa Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University Thailand, Email: kraichat.tan@mahidol.ac.th
Orawan Kaewboonchoo Department of Public Health Nursing, Faculty of Public Health, Mahidol University, Thailand, Email: orawan.kae@mahidol.ac.th
Siriphat Intrakun 1Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahcidol University Thailand, Email: siriphat.int@student.mahidol.ac.th https://orcid.org/0009-0001-1825-1006

Keywords:

Phthalates, Settled house dust, Health risk assessment, Children, Rural environment

Abstract

Phthalates are widely used chemicals that are not chemically bonded to materials. Therefore, they can be readily released into house dust. Children are at high risk of phthalate exposure through dust ingestion due to inadequate hygiene practices, which may adversely affect their health. Settled house dust samples were collected from 310 households of elementary school children in Phatthalung, Thailand, using a vacuum cleaner. Ten phthalates were then analyzed by gas chromatography-mass spectrometry. A quantitative health risk assessment for children via ingestion was conducted using the United States Environmental Protection Agency (US EPA) methodology. Di-2-ethylhexyl phthalate (DEHP) was the most abundantly detected compound, followed by di-n-octyl phthalate (DnOP) and dibutyl phthalate (DBP) (detection rates > 60%), with median concentrations ranging from 6.90 to 150.91 µ g/g. The median concentration of total phthalates (Σ10PAEs) was 190.71 µg/g. The median estimated daily intakes (EDIs) of DEHP, DnOP, DBP, and Σ10PAEs ranged from 3.95 to 112.56 ng/kg bw/day and 13.18 to 375.22 ng/kg bw/day under central-tendency and upper-percentile scenarios, respectively. The EDIs of DEHP, DnOP, and Σ10PAEs in children aged ≥ 9 years were significantly higher than those in younger children. The hazard quotient (HQ) and hazard index (HI) values for the three phthalates were less than 1. The CR for DEHP was below 1×10^-4; however, one child exceeded this threshold under the upper-percentile scenario (1.001×10^-4). These findings suggest that DEHP exposure warrants attention given its potential carcinogenic risk, highlighting the need for appropriate risk management strategies to reduce phthalate exposure in indoor environments.

References

Aldegunde-Louzao N, Lolo-Aira M, Herrero-Latorre C. Phthalate esters in clothing: A review. Environ Toxicol Pharmacol. 2024; 108: 104457. DOI: 10.1016/j.etap.2024.10445

Singh R, Sinha A. A critical review of recent advancements in the photocatalysis process, mechanism, and degradation pathways for the removal of phthalates from the contaminated water matrix. J Environ Manage. 2025; 377: 124663. DOI: 10.1016/j.jenvman.2025.124663

Promtes K, Kaewboonchoo O, Kawai T, Miyashita K, Panyapinyopol B, Kwonpongsagoon S, et al. Human exposure to phthalates from house dust in Bangkok, Thailand. J Environ Sci Health A Tox Hazard Subst Environ Eng. 2019; 54(13): 1269-76. DOI: 10.1080/10934529.2019.1637207

Zhao Y, Preece AS, Wan M, Hou J, Li Y, Deng Q, et al. Influence of indoor environmental parameters on phthalate concentrations in bedrooms. Environ Int. 2025; 198: 109447. DOI: 10.1016/j.envint.2025.109447

Sun C, Yang M, Zhang J, Qian Z, Tian L, Zhao Z, et al. Non-dietary exposure risk of phthalates for residents in Shanghai. Build Environ. 2025; 274: 112791. DOI: 10.1016/j.buildenv.2025.112791

Moschet C, Anumol T, Lew BM, Bennett DH, Young TM. Household dust as a repository of chemical accumulation: New insights from a comprehensive high-resolution mass spectrometric study. Environ Sci Technol. 2018; 52(5): 2878-87. DOI: 10.1021/acs.est.7b05767

Lunderberg DM, Kristensen K, Liu Y, Misztal PK, Tian Y, Arata C, et al. Characterizing airborne phthalate concentrations and dynamics in a normally occupied residence. Environ Sci Technol. 2019; 53(13): 7337-46. DOI: 10.1021/acs.est.9b02123

Bope A, Haines SR, Hegarty B, Weschler CJ, Peccia J, Dannemiller KC. Degradation of phthalate esters in floor dust at elevated relative humidity. Environ Sci Process Impacts. 2019; 21(8): 1268-79. DOI: 10.1039/c9em00050j

Shen HY, Zhang Y, Lu XY, Chen LB, Zhu NZ, Xiao H, et al. How indoor decoration materials contribute to phthalates pollution: Uncovering occurrences, sources, and their implications for environmental burdens in households. J Hazard Mater. 2025; 490: 137719. DOI: 10.1016/j.jhazmat.2025.137719

Saraga D. Indoor air in our homes: Common contaminants and their sources. In: New Perspectives in Indoor Air Quality. 1st ed. Amsterdam: Elsevier; 2025. p. 305-16.

Bekö G, Weschler CJ, Langer S, Callesen M, Toftum J, Clausen G. Children’s phthalate intakes and resultant cumulative exposures estimated from urine compared with estimates from dust ingestion, inhalation and dermal absorption in their homes and daycare centers. PLoS One. 2013; 8(4): e62442. DOI: 10.1371/journal.pone.0062442

Xue J, Zartarian V, Moya J, Freeman N, Beamer P, Black K, et al. A meta-analysis of children’s hand-to-mouth frequency data for estimating nondietary ingestion exposure. Risk Anal. 2007; 27(2): 411-20. DOI: 10.1111/j.1539-6924.2007.00893.x

Grindler NM, Vanderlinden L, Karthikraj R, Kannan K, Teal S, Polotsky AJ, et al. Exposure to phthalate, an endocrine disrupting chemical, alters the first trimester placental methylome and transcriptome in women. Sci Rep. 2018; 8: 6086. DOI: 10.1038/s41598-018-24505-w

Braun JM, Sathyanarayana S, Hauser R. Phthalate exposure and children’s health. Curr Opin Pediatr. 2013; 25(2): 247-54. DOI: 10.1097/MOP.0b013e32835e1eb6

Wang Y, Qian H. Phthalates and their impacts on human health. Healthcare. 2021; 9(5): 603. DOI: 10.3390/healthcare9050603

Huang PC, Chiou YH, Cho YH, Lee CW. Children’s exposure to phthalates in dust and soil in Southern Taiwan: A study following the phthalate incident in 2011. Sci Total Environ. 2019; 696: 133685. DOI: 10.1016/j.scitotenv.2019.133685

Ait Bamai Y, Araki A, Kawai T, Tsuboi T, Saito I, Yoshioka E, et al. Exposure to phthalates in house dust and associated allergies in children aged 6-12 years. Environ Int. 2016; 96: 16-23. DOI: 10.1016/j.envint.2016.08.025

Gao X, Cui L, Mu Y, Li J, Zhang Z, Zhang H, et al. Cumulative health risk in children and adolescents exposed to bis(2-ethylhexyl) phthalate (DEHP). Environ Res. 2023; 237(Pt 1): 116865. DOI: 10.1016/j.envres.2023.116865

Muenhor D, Moon HB, Lee S, Goosey E. Organophosphorus flame retardants and phthalates in floor and road dust from a manual e-waste dismantling facility and adjacent communities in Thailand. J Environ Sci Health A Tox Hazard Subst Environ Eng. 2018; 53(1): 79-90. DOI: 10.1080/10934529.2017.1369813

Lee BC, Yoon H, Lee B, Kim P, Moon HB, Kim Y. Occurrence of bisphenols and phthalates in indoor dust collected from Korean homes. J Ind Eng Chem. 2021; 99: 68-73. DOI: 10.1016/j.jiec.2021.03.051

hinohara N, Oguri T, Takagi M, Ueyama J, Isobe T. Evaluating the risk of phthalate and non-phthalate plasticizers in dust samples from 100 Japanese houses. Environ Int. 2024; 183: 108399. DOI: 10.1016/j.envint.2023.108399

Jung K, Oh H, Ryu JY, Kim DH, Lee S, Son BC, et al. Relationship between housing characteristics, lifestyle factors and phthalates exposure: The first Korean National Environmental Health Survey (2009-2011). Ann Occup Environ Med. 2015; 27: 33. DOI: 10.1186/s40557-015-0078-8

Zhao Y, Sun Y, Zhang Q, Zhang Q, Hou J. A method for evaluating indoor phthalate exposure levels in collected dust. MethodsX. 2021; 8: 101187. DOI: 10.1016/j.mex.2020.101187

U.S. Environmental Protection Agency. Exposure Factors Handbook Chapter 5 (Update): Soil and Dust Ingestion. Washington, DC: U.S. Environmental Protection Agency; 2017. Available on: https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=337521

Novitri SA, Betha OS, Yusman AT, Nurmansyah MI, Shavira RF, Dhilasari EM. Knowledge and behavior of household medicine storage: A study from the urban area of Jakarta, Indonesia. Public Health of Indonesia. 2024; 10(2): 108-17. DOI: 10.36685/phi.v10i2.781

U.S. Environmental Protection Agency. Guidelines for Human Exposure Assessment. Washington, DC: U.S. Environmental Protection Agency; 2019. Available on: https://www.epa.gov/sites/default/files/2020-01/documents/guidelines_for_human_exposure_assessment_final2019.pdf

U.S. Environmental Protection Agency. Di(2-ethylhexyl)phthalate (DEHP); CASRN 117-81-7. Washington, DC: U.S. Environmental Protection Agency; 1987. Available on: https://iris.epa.gov/static/pdfs/0014_summary.pdf

U.S. Environmental Protection Agency. Dibutyl phthalate; CASRN 84-74-2. Washington, DC: U.S. Environmental Protection Agency; 1987. Available on: https://iris.epa.gov/static/pdfs/0038_summary.pdf

Agency for Toxic Substances and Disease Registry. Toxicological profile for di-n-octyl phthalate. Atlanta: Agency for Toxic Substances and Disease Registry; 1997. Available on: https://www.atsdr.cdc.gov/toxprofiles/tp95.pdf

Wang L, Gong M, Xu Y, Zhang Y. Phthalates in dust collected from various indoor environments in Beijing, China and resulting non-dietary human exposure. Build Environ. 2017; 124: 315-22. DOI: 10.1016/j.buildenv.2017.08.006

Zhang L, Navaranjan G, Takaro TK, Bernstein S, Jantunen L, Lou W, et al. Di-(2-ethylhexyl) phthalate (DEHP) in house dust in Canadian homes: Behaviors and associations with housing characteristics and consumer products. Indoor Air. 2023; 2023: 4655289. DOI: 10.1155/2023/4655289

Lv J, Sun S, Wu R, Li X, Bai Y, Xu J, et al. Phthalate esters in dusts from different indoor and outdoor microenvironment and potential human health risk: A case study in Beijing. Environ Res. 2025; 266: 120513. DOI: 10.1016/j.envres.2024.120513

Li HL, Song WW, Zhang ZF, Ma WL, Gao CJ, Li J, et al. Phthalates in dormitory and house dust of northern Chinese cities: Occurrence, human exposure, and risk assessment. Sci Total Environ. 2016; 565: 496-502. DOI: 10.1016/j.scitotenv.2016.04.187

Anake WU, Nnamani EA. Levels and health risk assessments of phthalate acid esters in indoor dust of some microenvironments within Ikeja and Ota, Nigeria. Sci Rep. 2023; 13: 12007. DOI: 10.1038/s41598-023-38062-4

Al Qasmi NN, Al-Thaiban H, Helaleh MIH. Indoor phthalates from household dust in Qatar: Implications for non-dietary human exposure. Environ Sci Pollut Res. 2019; 26(1): 421-30. DOI: 10.1007/s11356-018-3636-1

Li X, Zheng N, Zhang W, An Q, Ji Y, Chen C, et al. Comprehensive assessment of phthalates in indoor dust across China between 2007 and 2019: Benefits from regulatory restrictions. Environ Pollut. 2024; 342: 123147. DOI: 10.1016/j.envpol.2023.123147

Laemun N, Kaewboonchoo O, Suwanmanee S, Limpanont Y, Kawai T, Premmanee J, et al. Phthalate concentrations in house dust, their associations with household characteristics, and spatial distribution across rural and urban areas in southern Thailand. Atmos Environ. 2026; 373: 121936. DOI: 10.1016/j.atmosenv.2026.121936

Laemun N, Tantrakarnapa K, Kaewboonchoo O, Panuwet P, Siriruttanapruk S, Boonyamalik P. Contamination of phthalates and policy recommendations for Thailand. J Chulabhorn Royal Acad. 2025;7(1):9-21. Available on: https://he02.tci-thaijo.org/index.php/jcra/article/view/269179

Chen LB, Gao CJ, Zhang Y, Shen HY, Lu XY, Huang C, et al. Phthalate acid esters (PAEs) in indoor dust from decoration material stores: Occurrence, sources, and health risks. Toxics. 2024;12(7):505. DOI: 10.3390/toxics12070505

Xiang W, Gong Q, Xu J, Li K, Yu F, Chen T, et al. Cumulative risk assessment of phthalates in edible vegetable oil consumed by Chinese residents. J Sci Food Agric. 2020; 100(3): 1124-31. DOI: 10.1002/jsfa.10121

Li X, Zhang W, Lv J, Liu W, Sun S, Guo C, et al. Distribution, source apportionment, and health risk assessment of phthalate esters in indoor dust samples across China. Environ Sci Eur. 2021; 33: 19. DOI: 10.1186/s12302-021-00457-3

Koch HM, Wittassek M, Brüning T, Angerer J, Heudorf U. Exposure to phthalates in 5-6 years old primary school starters in Germany: A human biomonitoring study and a cumulative risk assessment. Int J Hyg Environ Health. 2011; 214(3): 188-95. DOI: 10.1016/j.ijheh.2011.01.009

National Industrial Chemicals Notification and Assessment Scheme. Di-n-octyl phthalate (DnOP): Existing Chemical Hazard Assessment Report. Sydney: Australian Government Department of Health and Ageing; 2008. Available on: https://www.industrialchemicals.gov.au/sites/default/files/Di-n-octyl%20phthalate%20DnOP.pdf

Ashworth MJ, Chappell A, Ashmore E, Fowles J. Analysis and assessment of exposure to selected phthalates found in children’s toys in Christchurch, New Zealand. Int J Environ Res Public Health. 2018; 15(2): 200. DOI: 10.3390/ijerph15020200

Dueñ as-Moreno J, Mora A, Kumar M, Meng XZ, Mahlknecht J. Worldwide risk assessment of phthalates and bisphenol A in humans: The need for updating guidelines. Environ Int. 2023; 181: 108294. DOI: 10.1016/j.envint.2023.108294