Exposure to Aflatoxins Above Permissible Limits in Maize (Zea Mays) Meant for Consumption and Their Health Risk Estimations in the Volta Region of Ghana

doi:10.21203/rs.3.rs-495437/v1

Aflatoxin contamination in foods is a vital health challenge for low and middle-income countries in subtropical regions. Maize (Zea mays L.), a staple food most widely grown in Africa including Ghana, and extensively consumed as much as three times per day is a source of aflatoxin contamination owing to its susceptibility to fungal attack. This study aimed at evaluating aflatoxin levels above international (European Food Safety Authority, EFSA) and local (Ghana Standards Authority, GSA) standards and health risks associated with maize sampled from the Volta Region (Hohoe, Ho, Battor Dugame, and Keta) of Ghana. Total aflatoxins (AF_Total) and the constituent aflatoxins (AFB₁, AFB₂, AFG₁, and AFG₂) were measured with High-Performance Liquid Chromatography (HPLC). Risk assessments were also conducted using models prescribed by the Joint FAO/WHO Expert Committee on Additives (JECFA). The degree of occurrence of aflatoxins was observed to be in decreasing order of AFG₂< AFG₁< AFB₂<AFB₁and were within the ranges of 0.78±0.04-234.73±3.8 µg/kg, 0.47±0.03-21.6±0.33 µg/kg, 1.01±0.05-13.75±1.2 µg/kg and 0.66±0.06-5.51±0.26 µg/kg respectively. Out of the 100 samples analyzed for total aflatoxins (AF_Total), 68% exceeded the limits of EFSA and were of range 4.98±0.6-444.01±8.9 µg/kg whereas 58% and ranged between 12.12±1.4-444.01±8.9 µg/kg exceeded for GSA limits. Risk assessments of total aflatoxins (AF_Total) for infants, children, and adolescents, and adults ranged between 0.0083-0.3427 μg/Kg.bw/day, 0.116-4.8192, 0-0.0396 ng Aflatoxins kg⁻¹bwday⁻¹and 3.2868x10^-4-0.0136 for Estimated Daily Intake (EDI), Margin of Exposure (MOE), Average Potency, and Population Risks respectively. It was inferred that the consumption of maize posed adverse health effects on all age categories studied because all calculated MOE values were greater than 0.04 ngkg⁻¹bwday⁻¹.

Food Science & Technology

Aflatoxins

toxigenic fungi

maize

mycotoxins

cereals

Ghana

HPLC

Table 1: Geographical locations and some attributes of the origin of samples

Town in Volta Region	No. of samples	Agro-ecological zones	Rainfall (mm)	Temperature (^oC)	Coordinates
Hohoe	25/100	Deciduous Forest	1985	25.5	5.8143°N, 0.0747° E
Ho	25/100	Deciduous Forest	766	25	5.5608°N, 1.0586° W
Battor Dugame	25/100	Coastal Savannah	536.2	27.9	5° 47N, 0. 45° E
Keta	25/100	Coastal Savannah	897	28.4	6.2374°N, 0.4502° W

Table 2: Limits of Detection (LOD) and Quantification (LOQ) of aflatoxins AFB₁, AFB₂, AFG₁, AFG₂, and Total aflatoxins (µg/kg) measured by HPLC

Aflatoxin	Limits	Amount (µg/kg)
AFB1	LOD	0.20
	LOQ	0.60
AFB2	LOD	0.17
	LOQ	0.51
AFG1	LOD	0.26
	LOQ	0.78
AFG2	LOD	0.36
	LOQ	1.08

LOD-Limit of Detection

LOQ-Limit of Quantification

Table 3: Concentration of aflatoxin types in different maize samples from different locations in Hohoe, Volta Region, Ghana

		Concentrations of Aflatoxins (µg/kg)
Location	Code	AFB1	AFB2	AFG1	AFG2	Total
Hohoe	HH1	48.5±0.99	12.9±0.4	n.d	n.d	61.4±1.8
	HH2	9.67±0.47	4.40±0.3	2.99±0.03	n.d	17.06±1.1
	HH3	26.02±1.2	8.53±0.15	n.d	n.d	34.55±.0.9
	HH4	9.65±0.25	5.98±0.92	2.71±0.91	n.d	18.34±0.9
	HH5	15.29±0.39	3.11±0.5	1.81±0.05	1.97±0.06	23.24±0.32
	HH6	22.77±0.8	3.43±0.27	3.50±0.85		29.7±2.15
	HH7	9.03±1.7	2.93±0.04	1.87±0.05	n.d	13.83±0.22
	HH8	n.d	n.d	n.d	n.d	n.d
	HH9	7.82±0.6	4.69±0.03	n.d	n.d	12.51±0.26
	HH10	n.d	n.d	n.d	n.d	n.d
	HH11	n.d	n.d	n.d	n.d	n.d
	HH12	4.31±0.26	2.86±0.03	1.55±0.05	n.d	8.72±0.8
	HH13	47.75±2.25	5.23±0.25	2.98±0.9	1.66±0.06	57.62±1.2
	HH14	24.32±2.1	4.2±0.22	1.13±0.04	n.d	29.65±2.3
	HH15	12.92±0.5	5.1±0.07	1.41±0.91	n.d	19.43±0.65
	HH16	38.27±1.5	9.13±0.15	n.d	n.d	47.4±1.45
	HH17	7.18±0.25	2.68±0.02	n.d	n.d	9.86±0.26
	HH18	18.11±0.82	6.26±1.02	3.6±0.55	1.80±	25.77±0.4
	HH19	15.42±0.89	5.51±0.91	n.d	n.d	20.93±0.6
	HH20	27.77±0.99	2.98±0.03	n.d	n.d	30.75±0.98
	HH21	28.92±0.99	5.16±0.90	1.18±0.04	1.00±0.02	36.26±0.87
	HH22	n.d	n.d	n.d	n.d	n.d
	HH23	n.d	n.d	n.d	n.d	n.d
	HH24	n.d	n.d	n.d	n.d	n.d
	HH25	19.94±0.5	11.79±0.5	n.d	n.d	31.73±0.97

n.d- Not detected

Table 3b. Statistical summary of data from Hohoe

	AFB1	AFB2	AFG1	AFG2	AFTotal
Median	12.92	4.20	0.00	0.00	19.43
Std. Deviation	14.51	3.55	1.29	0.62	17.73
Variance	210.67	12.64	1.66	0.38	314.33
Skewness	0.87	0.79	0.91	2.19	0.65
Std. Error of Skewness	0.46	0.46	0.46	0.46	0.46
Kurtosis	0.12	0.49	-0.66	3.31	-0.38
Std. Error of Kurtosis	0.90	0.90	0.90	0.90	0.90
Percentiles 25	2.16	1.34	0.00	0.00	4.36
50	12.92	4.20	0.00	0.00	19.43
75	25.17	5.74	1.84	0.00	31.24

Table 4: Concentration of aflatoxin types in different maize samples from different locations in Ho, Volta Region of Ghana

		Concentrations of Aflatoxins (µg/kg)
Location	Code	AFB1	AFB2	AFG1	AFG2	Total
Ho	Ho1	n.d	n.d	n.d	n.d	n.d
	Ho2	32.88±1.4	12.61±0.05	n.d	n.d	45.49±0.35
	Ho3	25.29±0.24	n.d	3.51±0.14	n.d	28.8±0.45
	Ho4	117.44±4.2	14.86±2.44	6.22±0.2	2.06±0.17	140.58±5.1
	Ho5	25.7±1.26	9.56±0.03	n.d	n.d	35.26±1.3
	Ho6	58.07±2.32	10.52±1.2	n.d	n.d	68.6±1.50
	Ho7	42.92±1.2	15.0±0.42	4.2±0.26	n.d	62.12±2.45
	Ho8	4.20±0.51	2.7±0.50	1.6±0.05	n.d	8.5±0.95
	Ho9	n.d	n.d	n.d	n.d	n.d
	Ho10	n.d	n.d	n.d	n.d	n.d
	Ho11	19.83±1.2	n.d	n.d	n.d	19.83±1.20
	Ho12	39.42±1.22	17.19±0.1	n.d	n.d	56.61±1.20
	Ho13	22.33±0.35	14.77±0.48	n.d	n.d	37.1±1.4
	Ho14	20.73±0.3	8.53±0.48	n.d	n.d	29.26±1.4
	Ho15	n.d	n.d	n.d	n.d	n.d
	Ho16	n.d	n.d	n.d	n.d	n.d
	Ho17	48.35±0.60	20.77	n.d	n.d	69.12±3.60
	Ho18	14.97±0.43	9.97±	6.09±0.13	n.d	31.03±0.50
	Ho19	5.46±0.11	4.60±0.10	4.00±0.13	1.12±0.05	15.18±0.44
	Ho20	9.73±0.77	n.d	n.d	n.d	9.73±0.78
	Ho21	195.5±2.0	18.78±0.45	6.8±0.13	3.23±0.04	224.31±6.4
	Ho22	n.d	n.d	n.d	n.d	n.d
	Ho23	2.89±0.4	n.d	n.d	n.d	n.d
	Ho24	4.95±0.5	1.74±0.04	0.89±0.01	1.09±0.02	8.67±0.21
	Ho25	n.d	n.d	n.d	n.d	n.d

n.d- Not detected

Table 4b. Statistical summary of data from Ho

	AFB1	AFB2	AFG1	AFG2	AFTotal
Median	14.97	2.70	0.00	0.00	19.83
Std. Deviation	43.84	7.26	2.30	0.79	51.20
Variance	1922.48	52.65	5.29	0.62	2622.20
Skewness	2.84	0.60	1.49	2.89	2.54
Std. Error of Skewness	0.46	0.46	0.46	0.46	0.46
Kurtosis	9.12	-1.19	0.74	8.34	7.5
Std. Error of Kurtosis	0.90	0.90	0.90	0.90	0.90
Percentiles 25	0.00	0.00	0.00	0.00	0.00
50	14.97	2.70	0.00	0.00	19.83
75	36.15	13.69	2.55	0.00	51.05

Table 5: Concentration of aflatoxin types in different maize samples from different locations in Battor Dugame district of the Volta Region of Ghana

		Concentrations of Aflatoxins (µg/kg)
Location	Code	AFB1	AFB2	AFG1	AFG2	Total
Battor Dugame	BD1	50.55±1.65	15.68±1.5	10.21±1.1	2.7±0.6	79.14±2.1
	BD2	11.86±0.45	7.54±0.04	n.d	n.d	19.4±0.85
	BD3	n.d	n.d	n.d	n.d	n.d
	BD4	14.28±1.20	13.58±0.06	10.19±0.9	n.d	38.05±3.50
	BD5	n.d	n.d	n.d	n.d	n.d
	BD6	20.5±0.12	13.97	4.53±0.22	n.d	39.00±0.4
	BD7	48.18±0.6	16.32±1.3	11.5±1.22	2.8±0.12	78.80±1.84
	BD8	59.5±3.01	13.77±0.9	4.99±0.26	5.5±0.27	83.76±1.71
	BD9	44.42±2.24	n.d	n.d	n.d	44.42±2.24
	BD10	1.89±0.06	n.d	n.d	n.d	1.89±0.06
	BD11	2.26±0.6	n.d	n.d	n.d	2.26±0.6
	BD12	28.11±0.31	8.3±0.5	4.67±0.47	n.d	41.08±2.5
	BD13	43.7±2.25	21.6±0.33	13.75±1.2	n.d	79.05±1.82
	BD14	182.29±8.33	18.77±1.4	n.d	n.d	201.06±8.45
	BD15	n.d	n.d	n.d	n.d	n.d
	BD16	26.9±2.5	21.5±0.35	5.8±0.33	1.11±0.05	55.31±1.67
	BD17	85.2±0.35	31.4±1.2	n.d	n.d	116.6±2.14
	BD18	54.73±0.3	24.1±0.4	14.5±1.2	3.5±0.6	94.83±5.2
	BD19	n.d	n.d	n.d	n.d	n.d
	BD20	4.98±0.7	n.d	n.d	n.d	4.98±0.6
	BD21	41.11±1.5	11.35±0.9	n.d	n.d	52.46±0.4
	BD22	181.87±2.18	38.63±1.4	8.50	n.d	229.0±6.0
	BD23	85.74±0.4	31.00±1.1	n.d	n.d	116.74±2.11
	BD24	20.17±0.2	7.08±0.3	5.16±0.6	1.98±0.05	34.39±1.1
	BD25	81.85±0.33	32.95±1.2	13.41±1.1	4.89±0.7	133.1±2.3

n.d- Not detected

Table 5b. Statistical summary of data from Dzodze

	AFB1	AFB2	AFG1	AFG2	AFTotal
Median	28.11	13.58	0.00	0.00	44.42
Std. Deviation	49.91	12.04	5.24	1.66	61.59
Variance	2491.18	145.05	27.48	2.77	3739.67
Skewness	1.78	0.53	0.79	1.76	1.25
Std. Error of Skewness	0.46	0.46	0.46	0.46	0.46
Kurtosis	3.22	-0.72	-0.89	2.06	1.43
Std. Error of Kurtosis	0.90	0.90	0.90	0.90	0.90
Percentiles 25	3.62	0.00	0.00	0.00	3.62
50	28.11	13.58	0.00	0.00	44.42
75	57.12	21.55	9.35	1.54	89.30

Table 6: Concentration of aflatoxin types in different maize samples from different locations in Keta, Volta Region of Ghana

		Concentrations of Aflatoxins (µg/kg)
Location	Code	AFB1	AFB2	AFG1	AFG2	Total
Keta	KT1	n.d	n.d	n.d	n.d	n.d
	KT2	2.2±0.15	n.d	n.d	n.d	2.2±0.15
	KT3	n.d	n.d	n.d	n.d	n.d
	KT4	n.d	n.d	n.d	n.d	n.d
	KT5	338.3±8.6	103±2.5	2.71±0.12^cd	n.d	444.01±8.9
	KT6	102.1±2.5	0.88±0.03	n.d	n.d	102.98±2.5
	KT7	11.5±0.3	0.62±0.03	n.d	n.d	12.12±1.4
	KT8	5.21±0.32	1.5±0.06	n.d	n.d	6.71±0.08
	KT9	185.17±2.15	9.37±0.25	n.d	n.d	194.54±2.5
	KT10	18.21±1.31	2.66±0.13	n.d	n.d	20.87±0.35
	KT11	3.93±0.22	0.79±0.03	n.d	n.d	4.72±0.28
	KT12	n.d	n.d	n.d	n.d	n.d
	KT13	75.4±1.85	40.3±0.55	7.62±0.33	2.57±0.3	125.89±2.5
	KT14	24.7±0.35	6.77±0.30	2.61±0.92	n.d	34.08±3.01
	KT15	5.18±0.25	2.91±0.9	1.02±0.02	n.d	9.11±0.22
	KT16	25.96±0.31	7.89±0.32	1.22±0.06	n.d	35.07±2.82
	KT17	10.91±1.22	4.23±0.23	2.5±0.92	1.88±0.06	19.52±0.31
	KT18	27.78±0.52	9.47±0.46	5.41±0.25	5.51±0.26	48.17±0.55
	KT19	n.d	n.d	n.d	n.d	n.d
	KT20	n.d	n.d	n.d	n.d	n.d
	KT21	n.d	n.d	n.d	n.d	n.d
	KT22	n.d	n.d	n.d	n.d	n.d
	KT23	n.d	n.d	n.d	n.d	n.d
	KT24	n.d	n.d	n.d	n.d	n.d
	KT25	n.d	n.d	n.d	n.d	n.d

n.d- Not detected

Table 6b. Statistical summary of data from Keta (KT)

	AFB1	AFB2	AFG1	AFG2	AFTotal
Median	3.93	0.62	0.00	0.00	4.72
Std. Deviation	76.42	21.51	1.93	1.23	96.42
Variance	5840.63	462.76	3.71	1.52	9297.30
Skewness	3.24	4.07	2.48	3.51	3.46
Std. Error of Skewness	0.46	0.46	0.46	0.46	0.46
Kurtosis	11.20	17.57	6.15	12.99	13.25
Std. Error of Kurtosis	0.90	0.90	0.90	0.90	0.90
Percentiles 25	0.00	0.00	0.00	0.00	0.00
50	3.93	0.62	0.00	0.00	4.72
75	25.33	5.50	1.12	0.00	34.58

Table 7: Proportions of samples that exceeded AF_Total and AFB₁ and limits of the European Food Safety Authority (EFSA) and Ghana Standard Authority (GSA)

	Samples	Total samples	Exceeding EFSA regulation		Exceeding GSA regulation
			Yes (%)	Range	Yes (%)	Range
AFTotal	Hohoe	25	19 (76%)	8.72±0.8-61.4±1.8	17 (68%)	12.51±0.26-61.4±1.8
	Ho	25	17 (68%)	8.5±0.95-224.31±6.4	14 (56%)	15.18±0.44-224.31±6.4
	Battor Dugame	25	19 (76%)	4.98±0.6-229.0±6.0	18 (72%)	19.4±0.85-229.0±6.0
	Keta	25	13 (52%)	4.72±0.28-444.01±8.9	9 (36%)	12.12±1.4-444.01±8.9
	Total	100	68	4.98±0.6-444.01±8.9	58	12.12±1.4-444.01±8.9
AFB1
	Hohoe	25	19 (76%)	4.31±0.26-48.5±0.99	18 (72%)	7.18±0.25-48.5±0.99
	Ho	25	18 (72%)	2.89±0.4-195.5±2.0	15 (60%)	5.46±0.11-195.5±2.0
	Battor Dugame	25	20 (80%)	2.26±0.6-182.29±8.33	18 (72%)	11.86±0.45-182.29±8.33
	Keta	25	14 (56%)	3.93±0.22-338.3±8.6	13 (52%)	5.18±0.25- 338.3±8.6
	Total	100	71	2.26±0.6-338.3±8.6	64	5.18±0.25-338.3±8.6

European Union Food Safety (EFSA) limit for AF_Total = 4µg/kg

European Union Food Safety (EFSA) limit for AFB1 = 2µg/kg

Ghana Standards Authority (GSA) limit for AF_Total = 10µg/kg

Ghana Standards Authority (GSA) limit for AFB1 = 5µg/kg

Table 8: Evaluation of risk for Total Aflatoxins via consumption of maize

District/ Locality	Age Category	Estimated Daily Intake (EDI) (μg/ Kg.bw/day)	MOE	Av. Potency (ng Aflatoxins kg⁻¹bwday⁻¹)	Population Risk
Hohoe	Infants (6-52 mths)	0.1499	0.2668	0.0396	5.94x10^-3
	Children and adolescents (5-17yrs)	0.0519	0.7707	0.0396	3.05x10^-2
	Adults (18-60yrs)	0.0343	1.1662	0.0396	1.358x10^-3
Ho	Infants (6-52 mths)	0.1529	0.2616	0.0396	0.0298
	Children and adolescents (5-17yrs)	0.0530	0.7547	0.0396	2.0988x10^-3
	Adults (18-60yrs)	0.0349	1.1461	0.0396	1.3820x10^-3
Battor Dugame	Infants (6-52 mths)	0.3427	0.1167	0.0396	0.0136
	Children and adolescents (5-17yrs)	0.1188	0.3367	0.0396	4.704x10^-3
	Adults (18-60yrs)	0.0783	0.5109	0.0396	3.100x10^-3
Keta	Infants (6-52 mths)	0.0364	1.0989	0.0396	1.441x10^-3
	Children and adolescents (5-17yrs)	0.0126	3.1746	0.0396	4.9896x10^-4
	Adults (18-60yrs)	0.0083	4.8192	0.0396	3.2868x10^-4

Margin of Exposure-MOE

Median aflatoxins- Hohoe =19.43 µg/kg, Ho= 19.83 µg/kg, D= 44.42 µg/kg, KT= 4.72 µg/kg

Daily intake of maize for infants was halved (0.5x 0.107 kg/day)

Daily intake of 0.107 kg/day was used for children and adults

TD₅₀ = 0.2 ng/Kg.bw (1 ng=0.001 μg)

Table 9: The average weights for different age categories used in this study

Age Category	Average Weight (Kg)	References
Infants (6-52 mths)	7	(Glover-Amengor et al. 2016) (Abeshu et al. 2016)
Children and adolescents (5-17yrs)	40 (26-54)	(Organization 2006) (Biritwum et al. 2005)
Adults (18-60yrs)	60.7	(Walpole et al. 2012)

Exposure to Aflatoxins Above Permissible Limits in Maize (Zea Mays) Meant for Consumption and Their Health Risk Estimations in the Volta Region of Ghana

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