Arsenic species in rice and rice-based products consumed by toddlers in Switzerland

Figures & data

Figure 1. IC-ICP-MS chromatogram of arsenic species of certified rice flour NIST 1568b. As(III): Arsenite, MMA(V) monomethylarsonic acid, DMA(V): dimethylarsinic acid, As(V): arsenate.

Table 1. Concentration of total arsenic and arsenic species, expressed as µg As kg⁻¹ on total mass product, for each group of rice-based products.

			As speciation^a,c
Sample		Total As^a,b	∑As species^a,c,d	iAs^a,c,e	As(III)^a,c	As(V)^a,c	MMA(V)^a,c	DMA(V)^a,c
Rice grains – brown, N = 4	Mean	205	182	152	121	31.1	1.1	28.7
	Median	217	191	159	136	27.4	0.8	27.2
	Range	147–238	146–198	117–172	58–153	10.4–59.4	0.8–2.1	25.3–35.3
Rice grains – white, N = 27	Mean	143	136	94.0	73.5	21.4	1.4	40.4
	Median	158	153	111	85.6	14.3	0.8	28.8
	Range	6.7–281	6.2–253	5.6–188	5.6–144	0.5–63.4	0.3–3.6	0.4–151.3
Baby foods – dry form, N = 12	Mean	83.2	84.3	67.5	51.3	16.2	0.7	16.1
	Median	88.9	92.3	73.8	63.6	15.3	0.3	14.4
	Range	13.0–138	10.2–138	9.5–119	3.6–84.0	4.7–39.4	0.3–2.4	0.4–49.4
Baby foods – ready-to-eat form, N = 9	Mean	14.2	10.9	8.6	7.6	1.0	0.3	2.0
	Median	15.5	10.5	9.8	8.2	1.6	0.3	3.6
	Range	5.2–33.1	4.1–19.0	3.4–12.9	2.8–12.1	0.6–3.2	0.3–0.3	0.4–6.0
Milk rice, N = 6	Mean	14.9	11.2	9.0	8.4	0.6	0.3	1.9
	Median	12.7	8.9	7.8	7.2	0.6	0.3	1.2
	Range	10.9–24.9	8.0–17.6	6.5–13.2	6.3–12.6	0.2–1.4	0.3–0.3	0.4–4.1
Rice cereals, N = 7	Mean	278	267	204	165	39.3	2.0	60.3
	Median	244	249	211	130	33.2	0.4	30.5
	Range	65.4–630	59.3–585	45.9–331	31.7–281	9.5–116	0.3–6.1	13.4–248^f
Rice crackers, N = 25	Mean	168	154	134	122	12.4	0.6	19.2
	Median	154	130	107	97	11.7	0.8	16.1
	Range	46.6–361	44.4–311	40.0–279	35.2–256	3.1–27.7	0.3–1.9	2.6–44.0
Rice drinks, N = 15	Mean	19.4	19.3	16.9	7.1	9.2	0.3	2.0
	Median	21.7	20.2	17.3	5.9	6.5	0.3	0.4
	Range	5.2–28.0	5.5–37.5	4.8–34.0	0.4–20.3	0.7–28.8	0.3–0.8	0.4–9.8

^aMean, median, range (minimum–maximum value) – values were calculated using 1/2 LOD and 1/2 LOQ in case of value below LOD or LOQ.

^bValue obtained using ICP-MS, As total method.

^cValue obtained using IC-ICP-MS, As speciation method.

^d∑As species = As(III) + As(V) + MMA + DMA.

^eiAs = As(III) + As(V).

^fHigh value due to one sample (rice pops).

Table 2. Median and range of iAs concentration (µg kg⁻¹) in rice-based products (baby foods, dry form and ready-to-use form, rice cereals and rice crackers) destined for young children, from various study (US FDA, 2013; EFSA (European Food Safety Authority) 2014; Signes-Pastor et al. 2016b) and from the present study.

Study		N	Median and range iAs concentration
Signes-Pastor et al. (2016a)	Baby foods dry form	29	121 (56–268)
	Rice cereals	53	75 (8–323)
	Rice crackers	97	111 (18–211)
FDA (2013)	Baby foods dry form	85	114 (39–254)
	Rice cereals	105	91 (23–238)
	Rice crackers	199	79 (8–273)
EFSA 2014	Baby foods dry form	20	133^a (–)
	Baby foods ready-to-use form	6	107^a (–)
This study	Baby foods dry form	12	83^a (13–138)
	Baby foods ready-to-use form	9	14^a (5.2–33.1)
	Rice cereals	7	278^a (65.4–630)
	Rice crackers	25	168^a (46.6–361)

^aMean value instead median was used.

Table 3. Estimated dietary exposure to iAs for toddlers (all consumers)^a.

					iAs exposure
	Consumption^b		iAs concentration		Scenario A^e	Scenario B^e	Scenario C^e
Food category	Mean^c	P95^c	Mean^d	Max^d	Mean (cons.) × mean (conc.)	P95 (cons.) × mean (conc.)	P95 (cons.) × max (conc.)
Rice cereals^f	0.102	0.260	205	331	0.021	0.053	0.086
Milk rice	0.192	1.493	9.0	13.2	0.002	0.013	0.020
Baby food dry form	0.003	n.d.	67.5	119	<0.001	<0.001	<0.001
Baby food ready-to-use form	0.378	3.107	8.6	12.9	0.003	0.027	0.040
Rice cracker	0.01	n.d.	134	279	0.001	0.001	0.003
Rice drinks	0.201	n.d.	16.3	29.2	0.003	0.003	0.006
Rice grains^g	0.376	2.095	30.6	56.4	0.011	0.064	0.118
Rice dishes^g,h	0.376	2.095	9.2^i	16.9^i	0.003	0.021	0.039
Total					0.044	0.184	0.312

^aExcluding exposure via drinking water.

^bReferred to Banasiak et al. (2005) and BfR (2015).

^cUnit: g kg⁻¹ b.w. d⁻¹.

^dUnit: µg kg⁻¹.

^eUnit: µg kg⁻¹ b.w. d⁻¹.

^fGroup ‘snack with rice, sweet or savoury’.

^gAdapted from the dry mass to cooked rice, factor: 0.3 (Bognar 2002).

^hRice dishes assumed 30% content of rice.

ⁱAdapted from the measured data with rice grains.

n.d.: No data, for that reason the mean value was inserted; cons.: consumption; conc.: concentration; P95: 95th percentile.

In bold are those values which exceed the lower BMDL₀₁ of 0.3 µg kg⁻¹ b.w. d⁻¹ by EFSA (2009).

Table 4. Estimated dietary exposure to iAs for toddlers (only consumers)^a.

					iAs exposure
	Consumption^b		iAs concentration		Scenario A^e	Scenario B^e	Scenario C^e
Food category	Mean^c	P95^c	Mean^d	Max^d	Mean (cons.) × mean (conc.)	P95 (cons.) × mean (conc.)	P95 (cons.) × max (conc.)
Rice cereals^f	0.612	1.465	204.7	330.9	0.125	0.300	0.485
Milk rice	2.598	7.018	9.0	13.2	0.023	0.063	0.093
Baby food dry form	0.204	0.297	67.5	118.6	0.014	0.020	0.035
Baby food ready-to-use form	3.058	7.232	8.6	12.9	0.026	0.062	0.093
Rice cracker	0.237	0.423	133.8	278.5	0.032	0.057	0.118
Rice drinks	16.261	19.418	16.3	29.2	0.265	0.317	0.567
Rice grains^g	1.170	2.920	30.6	56.4	0.039	0.098	0.182
Rice dishes^g,h	2.202	4.076	9.2^i	16.9^i	0.022	0.041	0.076
Total					0.546	0.958	1.649

^aExcluding exposure via drinking water.

^bReferred to Banasiak et al. (2005) and BfR (2015).

^cUnit: g kg⁻¹ b.w. d⁻¹.

^dUnit: µg kg⁻¹.

^eUnit: µg kg⁻¹ b.w. d⁻¹.

^fGroup ‘snack with rice, sweet or savoury’.

^gAdapted from the dry mass to cooked rice, factor: 0.3 (Bognar 2002).

^hRice dishes assumed 30% content of rice.

ⁱAdapted from the measured data with rice grains.

n.d.: no data, for that reason the mean value was inserted; cons.: consumption; conc.: concentration; P95: 95th percentile.

In bold are those values which exceed the lower BMDL₀₁ of 0.3 µg kg⁻¹ b.w. d⁻¹ by EFSA (2009).

Table 5. Estimated exposure to iAs for toddlers via drinking water consumption.

			iAs exposure through drinking water
Age^a	Total drinking-water consumption		Scenario: 0.2 µg l^−1b,c		Scenario: 1.0 µg l^−1c		Scenario: 5.0 µg l^−1c		Scenario: 10.0 µg l^−1c
	Mean^d	P95^d	Mean (cons.)^e	P95 (cons.)^e	Mean (cons.)^e	P95 (cons.)^e	Mean (cons.)^e	P95 (cons.)^e	Mean (cons.)^e	P95 (cons.)^e
12	37	83	0.007	0.017	0.04	0.08	0.19	0.42	0.37	0.83
24	18	49	0.004	0.01	0.02	0.05	0.09	0.25	0.18	0.49
36	14	36	0.003	0.007	0.01	0.04	0.07	0.18	0.14	0.36

^aAge given in months.

^bMedian of the Swiss data (n ≈ 5000) (data from the food safety laboratories at FSVO, unpublished results).

^cAssumed iAs concentration in drinking water.

^dUnit: g kg⁻¹ b.w. d⁻¹.

^eUnit: µg kg⁻¹ b.w. d⁻¹.

In bold are those values which exceed the lower BMDL₀₁ of 0.3 µg kg⁻¹b.w. d⁻¹ by EFSA (2009).

Table 6. Estimated dietary exposure to DMA(V) for toddlers (all consumers).

					DMA(V) exposure
	Consumption^a		DMA(V) Concentration		Scenario A^d	Scenario B^d	Scenario C^d
Food category	Mean^b	P95^b	Mean^c	Max^c	Mean (cons.) × mean (conc.)	P95 (cons.) × mean (conc.)	P95 (cons.) × max (conc.)
Rice cereals^e	0.102	0.260	60.3	248	0.006	0.016	0.064
Milk rice	0.192	1.493	1.9	4.1	<0.001	0.003	0.006
Baby food dry form	0.003	n.d.	16.1	49.4	<0.001	<0.001	<0.001
Baby food ready-to-use form	0.378	3.107	2	6	0.001	0.006	0.019
Rice cracker	0.01	n.d.	19.2	44	<0.001	<0.001	<0.001
Rice drinks	0.201	n.d.	2	9.8	<0.001	0.000	0.002
Rice grains^f	0.376	2.095	11.7	50.3	0.005	0.027	0.105
Rice dishes^f,g	0.376	2.095	3.9^h	16.8^h	0.001	0.008	0.031
Total					0.013	0.060	0.227

^aReferred to Banasiak et al. (2005) and BfR (2015).

^bUnit: g kg⁻¹ b.w. d⁻¹.

^cUnit: µg kg⁻¹.

^dUnit: µg kg⁻¹ b.w. d⁻¹.

^eGroup ‘snack with rice, sweet or savoury’.

^fAdapted from the dry mass to cooked rice, factor: 0.3 (Bognar 2002).

^gRice dishes assumed 30% content of rice.

^hAdapted from the measured data with rice grains.

n.d.: No data, for that reason the mean value was inserted; cons.: consumption; conc.: concentration; P95: 95th percentile.

Table 7. Estimated dietary exposure to DMA(V) for toddlers (only consumers).

					DMA(V) exposure
	Consumption^a		DMA(V) concentration		Scenario A^d	Scenario B^d	Scenario C^d
Food category	Mean^b	P95^b	Mean^c	Max^c	Mean (cons.) × mean (conc.)	P95 (cons.) × mean (conc.)	P95 (cons.) × max (conc.)
Rice cereals^e	0.612	1.465	60.3	248	0.037	0.088	0.363
Milk rice	2.598	7.018	1.9	4.1	0.005	0.013	0.029
Baby food dry form	0.204	0.297	16.1	49.4	0.003	0.005	0.035
Baby food ready-to-use form	3.058	7.232	2	6	0.006	0.014	0.043
Rice cracker	0.237	0.423	19.2	44	0.005	0.008	0.019
Rice drinks	16.261	19.418	2	9.8	0.033	0.039	0.190
Rice grains^f	1.170	2.920	13.0		0.015	0.038	0.147
Rice dishes^f,g	2.202	4.076	4.3^h	^h	0.008	0.016	0.061
Total					0.112	0.221	0.887

^aReferred to Banasiak et al. (2005) and BfR (2015).

^bUnit: g kg⁻¹ b.w. d⁻¹.

^cunit: µg kg⁻¹.

^dUnit: µg kg⁻¹ b.w. d⁻¹.

^eGroup ‘snack with rice, sweet or savoury’.

^fAdapted from the dry mass to cooked rice, factor: 0.3 (Bognar 2002).

^gRice dishes assumed 30% content of rice.

^hAdapted from the measured data with rice grains.

cons.: Consumption; conc.: concentration; P95: 95th percentile.

Figure 2. The arsenic species profile (As(III), As(V), MMA(V), DMA(V)) among rice and rice-based products: rice grains – brown: 120.6, 31.1, 1.1, 28.7; rice grains – white: 73.5, 21.4, 1.4, 40.4; dry infant formula: 51.3, 16.2, 0.7, 16.1; infant formula – purée: 7.6, 1.0, 0.3, 2.0; rice cereals: 165.4, 39.3, 2.0, 60.3; milk rice:8.4, 0.6, 0.3, 1.9; rice crackers: 121.5, 12.4, 0.6, 19.2 and rice drinks: 7.1, 9.2, 0.3, 2.0. Concentrations are given in µg kg⁻¹.

Figure 3. Concentrations of DMA(V) in relationship with iAs concentrations in rice grains from the FDA US market survey and from the current study (Swiss market survey). Concentrations are given in µg kg⁻¹ or ppb. An amount of 150 µg kg⁻¹ is the limit for iAs in rice set by China, the EU limit is 200 µg kg⁻¹.

[FDA] Food and Drug Administration. 2013. Analytical results from inorganic arsenic in rice and rice products sampling September 2013. https://www.fda.gov/downloads/food/foodborneillnesscontaminants/metals/ucm352467.pdf.

 Google Scholar

[EFSA] European Food Safety Authority. 2014. Dietary exposure to inorganic arsenic in the European population. Efsa J. 12(3):3597.

 Google Scholar

Signes-Pastor AJ, Carey M, Meharg AA. 2016b. Inorganic arsenic in rice-based products for infants and young children. Food Chem. 191:128–134.

 PubMed Web of Science ®Google Scholar

Signes-Pastor AJ, Carey M, Carbonell-Barrachina AA, Moreno-Jimenez E, Green AJ, Meharg AA. 2016a. Geographical variation in inorganic arsenic in paddy field samples and commercial rice from the Iberian Peninsula. Food Chem. 202:356–363.

 PubMed Web of Science ®Google Scholar

Banasiak U, Heseker H, Sieke C, Sommerfeld C, Vohmann C. 2005. Abschätzung der Aufnahme von Pfanzenschutzmittel-Rückständen in der Nahrung mit neuen Verzehrsmengen für Kinder. Bundesgesundheitsbl - Gesundheitsforsch -Gesundheitsschutz. 48:84–98.

 PubMedGoogle Scholar

[BfR] Bundesinstitut für Risikobewertung, Deutschland. 2015. Arsen in Reis und Reisprodukten. Nr 018/2015. http://mobil.bfr.bund.de/cm/343/arsen-in-reis-und-reisprodukten.pdf.

 Google Scholar

Bognar A. 2002. Tables on weight yield of food and retention factors of food constituents for the calculation of nutrient composition of cooked foods (dishes). Berichte Des Bundesforschungsanstalt Für Ernährung. http://www.fao.org/uploads/media/bognar_bfe-r-02-03.pdf.

 Google Scholar

[EFSA] European Food Safety Authority. 2009. EFSA panel on contaminants in the food chain (CONTAM): scientific opinion on arsenic in food. Efsa J. 7(10):1351.

 Google Scholar