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Chapter: 5

Fluoride Toxicity Studies in Mehsana District, North Gujarat

General

A number of studies by different workers had been undertaken to investigate the adverse effects of high fluoride in drinking water on health in the Mehsana district. To place the results of these studies in a proper perspective, a summary table giving fluoride content in drinking water in a few villages is presented below (Table 4).

Table-4: Fluoride content in drinking water in a few villages in the district of Mehsana. (Source: RGNDWM survey data.)

Village Name	Fluoride content (ppm)	Village name	Fluoride content (ppm)	Village name	Fluoride content (ppm)
Gokharva	2.4	Litheda	9.9	Badarpur	4.0
Pinpharpur	1.5	Upera	5.9	Sarna	2.0
Kholwada	8.9	Khayasadu	1.6	Mirzapur	1.58
Thakrasan	3.6	Madhasana	2.8

Out of total of 1089 villages, 441 are reported to have more than permissible level (>1.5 ppm) of fluoride. A complete table giving recent data on fluoride concentration on all the 441 fluoride affected villages of Mehsana is given in Appendix 1. A summary table highlighting the extent of fluoride affected population is presented in Table 5. Out of 22 lakh total population of Mehsana District, 8.16 lakh (i.e., 39.8%) people consume the water with high fluoride concentration. According to the survey carried out by the Department of Health, cases of dental and skeletal fluorosis are reported in 236 villages. It is also noticed from this table that the average rate of water table decline was about 3m/yr during the period 1981 to 1989. This trend has only exacerbated in recent years.

For the sake of completeness we also give in Table 6a the summary status of water quality in Gujarat in terms of fluorides, nitrates and salinity. In

Table 6b are presented the minimum and maximum values of the above parameters, observed in excess of the ICMR permissible standards for drinking water. National and international standards of drinking water quality are presented in Table 7.

A survey was conducted in eighteen fluoride endemic villages in Mehsana district of north Gujarat (Chinoy et al, 1992a). The individuals affected with fluorosis were examined for apparent mottled teeth and skeletal complications. Samples of urine and blood of these individuals along with drinking water were collected and compared with samples obtained from Ahmedabad city population. The analysis of water, urine and blood showed significantly high fluoride levels in individuals affected with fluorosis. Several other parameters indicative of metabolic functions were analysed which clearly indicated adverse effect of high fluoride ingestion.

Table-5: Fluoride affected talukas of Mehsana district, Gujarat state.

Taluka Name	Total Villages	Affected villages	% Population drinking high fluoride water	Groundwater depletion rate (m/yr) (1981-1989)
Chanasma	110	62	55.6	--
Harij	39	33	82.0	2.78
Kadi	118	24	14.4	1.96
Kalol	68	1	1.5	2.77
Kheralu	167	93	57.4	2.16
Mehsana	109	1	0.3	3.57
Patan	140	86	58.0	6.12
Sami	98	59	55.6	1.52
Siddhpur	82	55	74.5	4.07
Vijapur	108	10	7.3	3.36
Visnagar	60	17	31.5	1.75
Total	1089	441	39.8	Average: 2.99

Table-6a: Status of water quality in Gujarat in terms of fluoride, nitrate and salinity.

Sr. No.	District	Total No. of villages surveyed	No. of villages having excess			% villages having excess
			Fluoride	Nitrate	Salinity	Fluoride	Nitrate	Salinity
1.	Ahmedabad	786	199	12	88	25.31	1.53	11.2
2.	Junagadh	1071	77	11	51	7.19	1.03	4.76
3.	Rajkot	854	38	7	30	4.45	0.82	3.51
4.	Surendranagar	652	63	1	47	9.66	0.15	7.21
5.	Amreli	623	80	58	10	12.84	10.91	1.61
6.	Bhavnagar	919	109	109	29	11.86	11.86	31.56
7.	Jamnagar	693	25	23	47	3.61	3.32	6.78
8.	Gnadhinagar	98	21	1	Nil	21.43	1.02	Nil
9.	Sabarkantha	1847	337	143	62	18.25	7.74	2.82
10.	Banaskantha	1556	418	58	74	26.86	3.73	4.76
11.	Bhuj	997	14	5	44	1.40	0.50	4.41
12.	Mehsana	1046	522	23	113	49.90	2.20	10.80
13.	Baroda	1651	293	50	65	17.75	3.03	3.94
14.	Kheda	973	220	85	150	22.61	8.74	15.42
15.	Bharuch	1123	33	42	108	2.94	3.74	9.62
16.	Surat	1190	27	26	42	2.27	2.18	3.53
17.	Panchmahals	1895	336	114	56	17.73	6.02	2.96
18.	Valsad	826	14	6	42	1.69	0.73	5.08
19.	Dangs	311	Nil	1	Nil	Nil	0.32	Nil
	Total	19111	2826	785	1048	14.79	4.11	5.48

Source: Gujarat Water Supply and Sewerage Board (GWSSB)

Table-6b: Status of water quality in Gujarat in terms of fluoride, nitrate and salinity -
minimum and maximum values observed in excess of ICMR permissible standards.

Sr. No	District	Fluoride (mg/l)		Nitrate (mg/l)		Salinity, TDS (mg/l)
		Min.	Max.	Min.	Max.	Min.	Max.
1.	Ahmedabad	1.65	6.90	122	587	2,012	8,586
2.	Junagadh	1.56	4.86	Nil	Nil	2,020	6,096
3.	Rajkot	1.58	4.10	142	177	2,016	25,800
4.	Surendranagar	1.60	10.0	106	333	2,012	20,170
5.	Amreli	1.60	5.50	103	239	2,060	8,628
6.	Bhavnagar	1.60	7.60	106	257	2,012	4,142
7.	Jamnagar	1.54	1.96	103	354	2,016	89,510
8.	Gandhinagar	2.05	2.36	Nil	Nil	Nil	Nil
9.	Sabarkantha	1.60	8.90	102	780	2,052	7,138
10.	Banaskantha	1.53	10.73	102	270	2,026	8,274
11.	Kachchh	2.0	2.80	142	177	2,030	13,3266
12.	Mehsana	1.52	6.95	106	532	2,024	29,676
13.	Baroda	1.51	9.24	103	306	2,002	24,990
14.	Kheda	1.56	4.68	105	354	2,006	13,200
15.	Bharuch	1.59	5.30	114	197	2,100	54,182
16.	Surat	2.10	3.55	104	246	2,020	6,640
17.	Panchmahals	1.54	12.9	106	890	2,010	10,060
18.	Valsad	1.56	1.64	Nil	Nil	2,058	10,840
19.	Dangs	Nil	Nil	Nil	Nil	Nil	Nil

Table-7: National and international standards of quality of drinking water supplies.

		International Standards WHO - 1971		I.C.M.R. New Delhi 1975 Second Edition		ISI 10500 1983		NDWM, DRD Govt. of India		IS 10500 - 1991
Sr. No.	Parameters	Highest Desirable limit	Maximum permissible limit	Highest Desirable limit	Maximum permissible limit	Highest Desirable limit	Maximum permissible limit	Highest Desirable limit	Maximum permissible limit	Desirable limit	Maximum permissible limit
1.	Colour	5 PCU	50 PCU	5 PCU	25 PCU	10 HU	50 HU	5 HU	25 HU	5 HU	25 HU
2.	Taste and Odour	UO	UO	UO	UO	UO	UO	UO	UO	UO	UO
3.	Turbidity	5 JTU	25 JTU	5 JTU	25 JTU	10 NTU	25 NTU	5 JTU	25 JTU	5 NTU	10 NTU
4.	TDS.(mg/l)	500	1,500	500	3,000	500	3,000	500	1,500	500	2,000
5.	pH	7.0 - 8.5	6.5 - 9.2	7.0 - 8.5	6.5 - 9.2	6.5 - 8.5	9.2	7.0 - 8.5	6.5 - 9.0	6.5 - 8.5	6.5 - 8.5
6.	Hardness (CaCO₃, mg/I)	100	500	300	600	300	600	300	600	300	600
7.	Calcium (Ca, mg/l)	75	200	75	200	75	200	75	200	75	200
8.	Magnesium (Mg, mg/l)	30	150	50	100	30	100	50	100	-	-
9.	Chloride (Cl, mg/l)	200	600	200	1,000	250	1,000	200	1,000	250	1,000
10.	Sulphate (SO₄, mg/l)	200	400	200	400	150	400	200	400	200	400
11.	Nitrate (NO₃, mg/l)	45	-	20	100	45	45	45	100	45	100
12.	Fluoride (F, mg/l)	0.7	1.0	1.0	1.5	0.6 - 1.2	1.5	1.0	1.5	1.0	1.5
13.	Iron (Fe, mg/l)	0.1	1.0	0.1	1.0	0.3	1.0	0.1	1.0	0.3	1.0
14.	Manganese (Mn mg/l)	0.05	0.5	0.1	0.5	0.1	0.5	0.1	0.5	0.1	0.3

Notes: PCU = Platinum Cobalt scale Unit. HU = Hazen Unit. JTU = Jackson Turbidity Unit. NTU = Nephelometric Turbidity Unit. UO = Unobjectionable

Fluoride toxicity on body fluids and metabolic indicators

The data of another study by Chinoy et al (1994) revealed that the fluoride content in serum of fluorotic population from endemic area of Mehsana was higher and haemoglobin content lower as compared to control population of Ahmedabad city. The serum cholesterol levels in affected individuals were not altered indicating that cholesterol metabolism was not affected. Serum transaminases (SGOT and SGPT) were significantly enhanced indicating alterations in liver function. The decline in serum protein levels but elevation in Na⁺, K⁺ might affect electrolyte balance and kidney function, contributing towards loss of water from the body and consequent reduction in body weight. These and a few other results on body fluids and metabolic function indicators are presented in Table 8.

Table-8: Comparison of body fluids and metabolic function indicators between the fluorotic subjects from Mehsana and normal individuals from Ahmedabad city.

Region	No. of Subjects	Range	Mean ± S.D.
Serum (fluoride content in ppm)
Ahmedabad	41	0.03 - 1.10	0.170± 036
Mehsana	39	0.07 - 2.10	0.216± 0.060
Haemoglobin (in gm %)
Ahmedabad	10	10.9 - 14.2	13.01± 2.65
Mehsana	54	7.8 - 14.0	11.51± 0.13
Serum protein (mg/100 ml)
Ahmedabad	10	86.05 - 128.08	104.66± 2.37
Mehsana	20	69.90 - 110.20	91.82± 5.15
Serum cholesterol (mg/100 ml)
Ahmedabad	10	158.80 - 208.60	179.10± 13.17
Mehsana	17	64.00 - 241.09	157.05± 11.59

Table-8: Contd.

Serum glutamate oxaloacetate transaminase (SGOT, Activity in mU/ml)
Ahmedabad	10	10.0 - 18.9	15.17± 0.87
Mehsana	19	18.0 - 60.1	36.63± 2.93
Serum glutamate pyruvate transaminase (SGPT, Activity in mU/ml)
Ahmedabad	10	4.0 - 18.0	10.35± 1.17
Mehsana	19	9.6 - 40.4	21.32± 2.30
Serum Na⁺(in ppm)
	6	2900 - 3500	3158± 275.8
	23	2800 - 7000	4577± 186.9
Serum K⁺(in ppm)
Ahmedabad		160 - 250	197.5± 29.3
Mehsana		210-970	512.6± 7.9
Catecholamines (epinepherine)
Ahmedabad	10	168 - 260	222± 33.7
Mehsana	30	166-392.5	264± 27
Catecholamines (nor epinepherine)
Ahmedabad	10	78 - 120	96.24± 19.3
Mehsana	30	75 - 157.4	103± 12
Thyroid (T3)
Ahmedabad	10	0.7 - 2
Mehsana	10	0.3 - 1.5
Thyroid (T4)
Ahmedabad	10	5.4 - 13.5
Mehsana	10	9.4 - 11.5
Thyroid (TSH)
Ahmedabad	10	0.2 - 5
Mehsana	10	0.3 - 2
Serum sialic acid concentration (m g/ml)
Ahmedabad	25	180 - 236	200± 0.88
Mehsana	68	114 - 223	168± 4

Analysis of fluoride in serum and urine of fluorotic individuals revealed that fluoride in serum is higher in affected individuals as compared to control population of Ahmedabad city. As a consequence, the general body metabolism would be affected.

The haemoglobin content in fluorotic population showed no significant alterations as compared to control population. However, Macuch et al. (1973) reported low haemoglobin content in people exposed to fluoride and those living in the vicinity of fluoride containing fertiliser industries. Such diverse results call for detailed studies in this direction.

The activities of serum transaminases were enhanced which would indicate liver damage, and its altered function in fluorotic cases in Mehsana district.

In fluorotic individuals, the serum cholesterol concentrations were not affected. Therefore, it is evident that fluoride does not affect cholesterol metabolism and adrenogenesis in fluorotic individuals. The decrease in serum protein levels in fluorotic population would indicate its reduced metabolism, since fluoride is known to inhabit the protein synthesis. This would in turn alter the osmotic balance and probably also the immunoglobin titres.

The serum electrolyte concentration (Na⁺, K⁺) were also significantly increased. These changes would affect the osmotic and electrolyte balance of blood leading to probable water loss from the body and consequently a reduction in body and organ weights. (Chinoy and Seqeria 1889a & b).

A survey was conducted in eighteen fluoride endemic villages in Mehsana district of north Gujarat (Chinoy et al, 1992b). The individuals affected with fluorosis were examined for apparent mottled teeth and skeletal complications samples of urine and blood of these individuals along with drinking water were collected and compared with samples obtained from Ahmedabad city population. The serum Catecholamines were increased significantly which might be due to the stress caused by accumulated fluoride. These elevated Catecholamines would have a stimulatory effect on the sympathetic nervous system and thereby influence the hypothalamus-gonadal axis and result in marked changes in the reproductive functions. As a consequence of enhanced Catecholamines, the carbohydrate metabolism will also be affected. However, the urinary Catecholamines were not influenced by fluoride intake. Chinoy et al (1992b) have reported in their studies on effect of fluoride in 36 villages of Mehsana district, North Gujarat that, the concentration of sialic acid was decreased significantly (P<0.01) in the fluorotic population as compared to control population. Sialic acid concentration is a marker for detection of fluorosis. Sialic acid, a sialomucoprotein maintains equilibrium with its derivatives, the glycosaminoglycans in the serum. The latter are known to attach themselves to exogenous proteins of the plasma membrane by glycosidic and glucosidic bonds and thus play an important role in the interaction of hormone membrane bound receptor molecules. Hence, the above mentioned alterations in sialic acid might cause disturbance in hormone action at the largest cell in fluorotic cases.

The study also revealed that the serum cholesterol and testosterone levels of fluoride afflicted subjects are found to be unaffected. However, conversion of testosterone into its potent metabolite may be altered due to high fluoride. Also the hormone-receptor interaction and consequent target organ response may be impaired due to increase in prostaglandins, E2 and PGF2. Both these prostaglandin are known to manifest anti-androgen effects on the male reproductive system. Prevalence of infertility among residents of high fluoride endemic areas of Andhra Pradesh (Neelam et al, 1987) may have been caused by such effects of fluoride on reproductive systems.

Genotoxic effects of fluoride in Mehsana

Sister Chromatid Exchange (SCE) test was utilised in a study to investigate the Genotoxic effects of fluoride in Mehsana district by Sheth et al. (1994). The results from cultured human lymphocytes indicated a significant increase in the frequency of SCE in the fluoride afflicted populations compared to normal population. This means that chromosomal alterations and chromosome aberrations are higher than in normal persons due to excess fluoride in drinking water.

Chapter: 6