Analysis of the fluoride levels of well water and tea consumed by the Moroccan population in different rural areas.

Table 1. Fluoride (mg/l) content of well water samples in the different regions. Sample Region Location Fluoride (mg/l) P1 Had Soualem-Berrechid Had Soualem 1.400 P2 Had Soualem-Berrechid Had Soualem 6.580 P3 Had Soualem-Berrechid Harcha 0.400 P4 Had Soualem-Berrechid Ouled Bouziri 2.550 P5 Kenitra Douar Bourhma 0.790 P6 Kenitra Douar Bourhma 0.530 P7 Kenitra Douar Bourhma 1.660 P8 Kenitra Kenitra 0.530 P9

Abstract

Fluoride plays a fundamental part in human health. However, continued ingestion of excessive fluoride may cause significant negative health effects on people, ranging from mild dental fluorosis to crippling skeletal fluorosis, depending on the level and time of exposure to fluorides. In provincial areas, the presence of fluoride in well water may be due to natural factors or human activities. The reason for our work was to evaluate the level of tainting of groundwater by fluorides from various areas in Morocco situated in rural and agricultural areas, where the main wellspring of consumable water is well water, and the reasons for fluorosis in this area. The 44 samples were taken in seven Moroccan regions: Had Soualem-Berrechid, Kenitra, Fez, Tit Mellil, Sidi Slimane-Sidi Kacem-Zirara, Larache, and Brachoua, and 12 samples of tea were taken from different souks and commercials in Morocco. Fluoride dosing measurements in well water were performed using the potentiometric technique using the fluoride-specific ion electrode (HI-4110) at room temperature, while the determination of fluorine in tea is done by the spectrophotometric method. The results of fluoride levels revealed in different well waters from different regions range from 0.2 to 6.58 mg/l. For the green and black tea samples, the fluorine content varies between 0.48 and 1.60 mg/l for the 10 min infusion and between 0.93 and 2.7 mg/l for the 30 min infusion. These results make it possible to warn the population facing the risk of developing dental fluorosis by limiting the amount of fluoride ingested by the consumed foods.

*The full-text study is online at https://www.sciencedirect.com/science/article/pii/S2214785322049999#!

Excerpt:

Table 1. Fluoride (mg/l) content of well water samples in the different regions.

Sample	Region	Location	Fluoride (mg/l)
P1	Had Soualem-Berrechid	Had Soualem	1.400
P2	Had Soualem-Berrechid	Had Soualem	6.580
P3	Had Soualem-Berrechid	Harcha	0.400
P4	Had Soualem-Berrechid	Ouled Bouziri	2.550
P5	Kenitra	Douar Bourhma	0.790
P6	Kenitra	Douar Bourhma	0.530
P7	Kenitra	Douar Bourhma	1.660
P8	Kenitra	Kenitra	0.530
P9	Kenitra	Kenitra	0.290
P10	Fez	Douar Bsais	0.730
P11	Fez	Douar Bsais	0.680
P12	Fez	Douar Chejeaa	0.450
P13	Fez	Douar Chejeaa	1.640
P14	Fez	Taaounyat Birda, Btamat Boujlafa	0.770
P15	Fez	Taaounyat Elfarah	0.970
P16	Fez	Taaounyat Ghalya	0.980
P17	Fez	Moulay Yacoub	0.850
P18	Fez	Moulay Yacoub	0.870
P19	Fez	Moulay Yacoub	0.090
P20	Fez	Moulay Yacoub	0.140
P21	Fez	Moulay Yacoub	0.180
P22	Tit Mellil	Tit Mellil	1.290
P23	Tit Mellil	Tit Mellil	1.470
P24	Tit Mellil	Tit Mellil	0.500
P25	Sidi Kacem-Sidi Slimane	Lkhawass	4.110
P26	Sidi Kacem-Sidi Slimane	Lkhawass	2.060
P27	Sidi Kacem-Sidi Slimane	Zirara	1.170
P28	Sidi Kacem-Sidi Slimane	Zirara	0.270
P29	Sidi Kacem-Sidi Slimane	Sidi Kacem	0.200
P30	Larache	Oulad Hamou Lghaba	0.750
P31	Larache	Oulad Hamou Lghaba	0.013
P32	Larache	Oulad Hamou Lghaba	0.004
P33	Larache	Oulad Hamou Lghaba	0.090
P34	Larache	Oulad Khssiss	0.200
P35	Brachoua	Enakhlat	0.650
P36	Brachoua	Enakhlat	0.790
P37	Brachoua	Enakhlat	0.330
P38	Brachoua	Enakhlat	0.460
P39	Brachoua	Brachoua	0.870
P40	Brachoua	Brachoua	0.270
P41	Temara	Jammat sbah, wladhbri	0.240
P42	Temara	Jammat sbah, wladhbri	0.250
P43	Temara	Jammat sbah, oulad mssoun rkhokha	0.220
P44	Temara	Jammat sbah, oulad mssoun rkhokha	0.040

Table 2. Fluoride level in green and black teas (10 and 30 mintes of infusion).

Sample	Nature	F^– mg/l (preparation 10 min)	F- mg/l (preparation 30 min)
1	Green tea	0.92	2.70
2	Green tea	1.17	2.20
3	Green tea	0.80	0.93
4	Green tea	1.40	1.93
5	Green tea	1.62	2.40
6	Green tea	0.50	1.94
7	Green tea	1.28	1.50
8	Green tea	0.69	2.55
9	Black tea	1.09	1.37
10	Black tea	1.26	1.75
11	Black tea	0.48	1.35
12	Black tea	1.26	1.36

2.2. Methods

Fluoride dosing has been made utilizing the potentiometric technique using the Fluoride specific ion electrode (HI-4110) at room temperature. HI-4110 is an ISE fluoride combination ideal for detecting free fluoride in drinking water, soft drinks, wine, plants, emulsion food products, and electrodeposition acids. The HI-4110 allows accurate measurement of the total concentration of fluoride.

The levels of fluoride in tea extracts (in duplicate tests) are determined by the Belcher-West colorimetric method with Alizarin complexone in polyethylene tubes [12]. In the presence of Alizarin complexone, lanthanum nitrate gives a red coloration in an aqueous medium. In the presence of F-anion, a blue-colored complex is formed. The new complex is soluble in acetone and was determined by spectrophotometry at 618 nm. The absorbance of the samples is subtracted from that of a control in which the tea extract is replaced by distilled water. The fluoride concentration of the samples is calculated by analysis against the calibration curve.