Role of Fluoride on Soil, Plant and Human Health: A Review on Its Sources, Toxicity and Mitigation Strategies

In recent scenario, fluorosis is now going to be a severe problem throughout the globe due to toxic effects of fluoride (F) on both plants, animals and humans. Natural geological sources and increased industrialization have contributed greatly to the increasing incidence of F-induced human and animal health issues. The toxic effects of high doses of F may adversely affect human health by causing skeletal fluorosis, dental fluorosis, bone fractures, the formation of kidney stones, decreased birth rates, weakening of thyroid functionality and impair intelligence, particularly in children. High concentrations of F in soil may seriously threaten the life of plants, devastate soil microbial activity, disrupt the soil ecology and causes soil and water pollution. Hydrogen fluorides (HF) in gaseous form accumulated in the leaves of sensitive plants against a concentration gradient and HF mainly damages the plant by entering into its body in the form of gas and affects a variety of plant physiological processes. In this review we discuss about the effect of fluoride toxicity on plant, human and soil health and its mitigation strategies.

Evaluation of phytotoxicity and genotoxicity of uranyl nitrate in Allium assay system.

Uranyl nitrate inhibited root growth of Allium cepa at > or = 25 microM concentration. Fluorimetric analysis of metal uptake indicated the entry and accumulation of uranium into the root cell. Uranyl nitrate was neither clastogenic nor aneugenic as it failed to induce micronuclei significantly, but between 25 and 100 microM concentration, it increased significantly the frequency of sister chromatid exchange over that of control, implying its genotoxicity that possibly interfered with DNA replication and/or repair process.

Hypohaptoglobinaemia as a biochemical and epidemiological marker of falciparum malaria.

OBJECTIVES: The study was conducted in two parts to find out the usefulness of hypohaptoglobinemia (Hpo) as a biochemical and epidemiological marker of malaria. Part-I study was conducted in a Medical College Hospital to find out Hpo in malaria and the time required for normalization of Hpo. Part-II study was undertaken in two endemic areas of malaria to find out the prevalence of Hpo and haptoglobin index (HI) throughout the year along with other indicators of malaria. METHODS: In Part-I study, 172 patients of malaria constituting 58, 52 and 62 patients of cerebral malaria, uncomplicated falciparum malaria and vivax malaria, respectively were enrolled. Along with routine haematological and biochemical investigations, haptoglobin (Hp) estimation was done by endoplate haptoglobin test kit on admission and at 15 days interval for 3 months. In Part-II study Hp was estimated is 305 subjects in two endemic areas of malaria. HI, parasitic index, slide positivity rate (SPR), slide falciparum rate (SFR) were estimated throughout the year and HI was compared with these epidemiological markers. RESULTS: Hpo was present in 102 (92.7%) cases of falciparum malaria which was significantly more than vivax malaria and non-malarial fever. The normalisation of Hpo took about a month or more. The incidence of Hpo was 32.1% is endemic and 4.7% in nonendemic area of malaria. The HI varied between 12.4 to 25.2% throughout the year and was found to be a better marker than other classical markers of malaria. CONCLUSION: Hypohaptoglobinemia may be considered as a useful indirect indicator of falciparum malaria. HI can be used as an epidemiological maker which is better than classical markers of malaria used at present.

An analytical presentation of drug resistance in Plasmodium falciparum and guidelines to formulate a drug strategy.

The present paper describes the advantage/limitation of presently available 'in-vivo' methods to detect sensitivity status of Plasmodium falciparum to commonly used antimalarial drugs. The paper is based on a retrospective analysis of 890 P. falciparum cases and various parameters used to define the level of drug resistance. The presented quantification methodology with weightage system to different epidemiological variables of resistance may provide a guideline as to the level of parasite resistance, and a switch over to another antimalarial of firstline treatment which is of the considerable importance to provide early diagnosis and prompt treatment to avert the severe cases/deaths due to malaria.

Plasmodium falciparum sensitivity in "in-vivo" and its distribution in geo-ecological zones of Gujarat.

Plasmodium falciparum sensitivity test in "in-vivo" carried out in 450 patients revealed, parasite clearance in 66.45 percent cases with 25 mgm/kg body wt of chloroquine. Mean parasite clearance time (MPCT) of sensitive and R I, resistant cases reached near parallelism with an early recrudescence in RI cases indicating stabilisation of genetic change in the parasite strain. The analysis of data revealed that proportionately higher resistance was recorded in coastal area having deciduous (wet) forest ecotype followed by plains of deciduous dry forest and semi arid/arid ecotypes.