4. Health Risk Assessment of Methylsiloxane for Different Exposure Routes .

					Exposure range for normal exposure scenarios (ng/kg/day)
Exposure Route	Time	Region	Population	Formula	ΣcVMS	ΣlMS	Reference Value (ng/kg bw/day)	Reference
Inhalation	2020–2021	WWTPs, Portugal	Maintenance Technicians	c	9,770 ± 1630 ng/kg/year		cRfDs of D4 and D5:150,000
			Managers		8,010 ± 722 ng/kg/year
			Laboratory Technicians		5410 ± 874 ng/kg/year
	2021	WWTPs, China	wastewater treatment technicians	a	9,700–44,000		cRfDs of D4 and D5:150,000
			laboratory technicians		4,300–28,000
			sludge treatment technicians		4,600–25,000
			office staff		4,700–24,000
	2019	Shengli oilfield, Dongying, China	Workers	b	8,170–202,000 ng/day	280–6,500 ng/day	
	2017	Southwest China	Workers	d	30,000–79,000	530–14,000	
	2021	Near a refinery in China	Children	a	300–2,100		cRfDs of D4 and D5:150,000
	2016–2017	Hanoi, Bacninh, Thaibinh, and Tuyenquang, Vietnam	Resident adults >18 years of age		1.47–20.4	3.78–16.4	
			Adolescents at 11–17 years of age		2.02–28.0	5.20–22.6
			Middle childhood at 6–10 years of age		2.87–39.8	7.40–32.1
			Early childhood at 1–5 years of age		3.35–46.5	8.63–37.4
			Infants at 6–12 months of age		5.38–74.7	13.9–60.2
	2016	Uppsala, Sweden	Adults at 26–61 years of age	c	61–440 (Home)		RfD: 630,000
					34–200 (Offices)	
	2014	Greece	Resident adults		2.48		NOAEL of D5:19,000,000
			Adolescents		3.13
			Children		5.57
			Toddlers		11.9
			Infants		11.1
	2014	Albany, USA	Resident adults		270		
			Teenagers at 11–18 years of age		340
			Children at 3–11 years of age		760
			Toddlers at 1–3 years of age		1,590
			Infants <1 year of age		3,180
	2014	Bathroom, Porto, Portugal	Adults	e	160		NOEL of D4:16,000,000;
			Children		3		NOEL of D5:5,400,000
	2021	Southwest China City	Resident adults	a	370–340		cRfDs of D4 and D5:150,000
	2018	Southwest China City	Residents >18 years of age	a	210–320	0.030–0.032	cRfDs of D4 and D5:150,000
			6–17 years old		230–420	0.011–0.042
			3–6 years old		380–620	0.018–0.062
			0–3 years old		690–720	0.069–0.072
			College students at 18–24 years of age		220–3,600	0.011–680
Ingestion of particulate matter and dust	2011, 2015, 2021	Interior of the Korean household	Resident adults	n	0.13–1.54	0.59–21.1	
			Children		0.81–9.31	3.53–127
	2021	Beijing, China	Sales clerks	o	0.025–2.83		
	2018	Henan, China	Resident adults	i	0.35	0.72	
			Teenagers		0.42	0.86
			Children		0.69	1.41
			Toddlers		2.10	4.31
			Infants		1.78	3.65
	2018	Universities, Southwestern China	College Students	o	75–1,200	150–110,000	
	2017	Southwest China	Workers	j	8.9–30	180–5,800	
	2016	Road dust, Hefei, China	Adults	o	0.008		
			Children		0.065
		Tianjin, China	Barbers	o	2.67		
Ingestion of food	2016	Barcelona, Spain (Fish)	Residents >60 years of age		43–46		
			20–60 years old		40–51
			10–19 years old		50–52
			6–9 years old		93–110
	2024	Beijing, China	Adults	k	10.31–241.13 (Fried chicken)		
					4.77–127.31 (French fries)		
Oral exposure to silicone-containing products	2017	China	Children aged 3 and under	n	0.44–18.05	0.41–20.74	
Dermal Exposure	2014	Porto, Portugal (PCP)	Adults	o	25,040		NOEL of D4:960,000,000;
			Children		350		NOEL of D5:1,600,000,000
	2011, 2015, 2021	South Korea (Dust)	Adults	n	0.08–0.92	0.35–12.6	
			Children		0.26–3.02	1.14–41.3
	2021	City in Southwest China	Adults	o	1,200–3,800		cRfDs of D4 and D5:67,000
	2018	Universities, Southwestern China	College Students	o	1,500–5,400 (PCP)	970–3,900 (PCP)	cRfDs of D4 and D5:67,000
					0.00051–0.0070 (Dust)	0.0012–0.65 (Dust)

^aVMS, volatile methylsiloxanes; WWTPs, wastewater treatment plants; cRfD, chronic reference dose; NOAEL, no observed adverse effect level; NOEL, no-observed effect level.

^bExposure of individual target substances.

^cMedian.

^dMean.

^e5th to 95th percentile.