No tests to diagnose toxicity are available.
The scary implication here is that you or your children could be dying of fluoride poisoning, and there is no way your doctor could ever know, because there isn't a single blood test that will report on the fact. The truth is that the medical profession can diagnose fluoride poisoning.
In the paragraph above the line you cite:
The earliest signs are chalky-white, irregularly distributed patches on the surface of the enamel; these patches become stained yellow or brown, producing a characteristic mottled appearance. Severe toxicity weakens the enamel, pitting its surface.
So, long-term fluoride poisoning has a distinct medical sign, especially in children.
Diagnoses of Fluoride Toxicity is documented by Medscape
It discusses patient presentation, and differential diagnoses, so other poisonings are not confused with it.
It suggests the following tests when fluoride poisoning is suspected:
- Serum electrolytes
- Electrocardiogram and cardiac monitoring
- Effects of hyperkalemia (peaked T waves, widened QRS, bradycardia, atrioventricular [AV] nodal blockade)
- Effects of hypocalcemia (prolonged corrected QT interval [QTc])
- Serum and urine fluoride levels are not available for ED evaluation.
- Perform a Dextrostix evaluation (fingerstick) on all patients with seizure and altered mental status because of the risk for hypoglycemia with systemic fluoride toxicity.
Are there currently no tests available to diagnose fluoride [...] toxicity?
Susheela, A.K. and Das, T.K. 1988 Fluoride toxicity and fluorosis: diagnostic test for early detection and preventive medicines adopted in India. [Abstract], International Symposium on Environmental Life Elements and Health, Beijing, 89.
... or fluorine toxicity?
Fluorine is a pale yellow gas. It is highly reactive (e.g. water burns with a bright flame in fluorine). Consequently people generally don't come into contact with fluorine.