Toxicity and degradation of the insecticide monocrotophos

Environmental Chemistry Letters - Monocrotophos, commonly named Azodrin or Nuvacron, is an organophosphate insecticide, which in spite of ban is preferred due to its high efficacy against...     

Antiviral Effects of Lactococcus lactis on Feline Calicivirus,A Human Norovirus Surrogate

Foodborne viruses, particularly human norovirus (NV) and hepatitis virus type A, are a cause of concern for public health making it necessary to explore novel and effective techniques for prevention of foodborne viral contamination, especially in minimally processed and ready-to-eat foods. This study aimed to determine the antiviral activity of a probiotic lactic acid bacterium (LAB) against feline calicivirus (FCV), a surrogate of human NV. Bacterial growth medium filtrate (BGMF) of Lactococcus lactis subsp. lactis LM0230 and its bacterial cell suspension (BCS) were evaluated separately for their antiviral activity against FCV grown in Crandell–Reese feline kidney (CRFK) cells. No significant antiviral effect was seen when CRFK cells were pre-treated with either BGMF (raw or pH 7-adjusted BGMF) or BCS. However, pre-treatment of FCV with BGMF and BCS resulted in a reduction in virus titers of 1.3 log₁₀ tissue culture infectious dose (TCID)₅₀ and 1.8 log₁₀ TCID₅₀, respectively. The highest reductions in FCV infectivity were obtained when CRFK cells were co-treated with FCV and pH 7-adjusted BGMF or with FCV and BCS (7.5 log₁₀ TCID₅₀ and 6.0 log₁₀ TCID₅₀, respectively). These preliminary results are encouraging and indicate the need for continued studies on the role of probiotics and LAB on inactivation of viruses in various types of foods.     

In-situ monitoring of chromium cytotoxicity in sugarcane

The potential of in-situ monitoring of cytotoxic effects of chromium through root-tip assay was studied in a sugarcane cultivar CoLk 8102 (Saccharum spp. hybrid). Sugarcane setts supplied with graded concentrations of chromium (VI), exhibited a reduction of 85.92 and 95.10 % in mean root length at 40 and 80 ppm Cr dosages along with 61.25 and 82.50% reduction in mean root number/node respectively. Mitotic index of root tip cells of treated setts declined and the frequency of aberrant mitotic phases increased pari passu to the increasing chromium concentration. To compare and quantify the effect of graded chromium dosages on frequency of chromosome aberrations vis-à-vis inhibition of mitotic activity, a 'Decretion factor' (D.F.) has been used for the first time. The value of DF increased with the increase in the chromium dosages. The increase in chromosome aberration frequency was low at low chromium dosages (1 or 2 ppm), but the high Cr dosages (40 and 80 ppm), induced sharp reduction in mitotic efficiency of root system along with anomalies in the process of cell division and induced chromosome aberrations in sugarcane root meristem, which in turn affected the over all plant growth.     

Study of fluoride content in groundwater of Nawa Tehsil in Nagaur, Rajasthan

There is a severe fluoride problem in Nawa tehsil of Nagaur district. Villagers are suffering from dental fluorosis and skeletal fluorosis. So an extensive geochemical study of 27 villages of eastern, south-eastern and southern zone of Nawa tehsil was done. Total 46 ground water samples were collected and analyzed for various physicochemical parameters as well as fluoride content. The ground water samples collected in clean polyethylene plastic containers were analyzed for pH, electrical conductivity, total dissolved salts, calcium, magnesium, total hardness, chloride and alkalinity. The fluoride concentration in the three different zones ranged from 0.64 to 14.62 mg l(-1) where 13.04% samples were found within permissible limit while 86.96% had fluoride beyond permissible limit (> 1.5 mg l(-1)). It was found that among the three different zones south-eastern zone was under serious fluoride contamination where fluoride concentration ranged between 1.10 to 14.62 mg l(-1). In the eastern zone fluoride concentration was recorded from 1.52 to 5.13 mg l(-1) whereas in the southern zone it was found between 0.64 to 3.63 mg l(-1).     

Some notes on the population dynamics of the monogenean gill parasite Gastrocotyle indica

The fish Caranx kalla of different size groups (2 to 18 cm body length) is present during various calender months of the year off the Madras coast (S. India). C. kalla displays a definite progressive shift in growth during successive months; the fish grows from 2 cm (September) to about 18 cm (August) over a period of 12 months. The highest (47%) or lowest (11%) incidence of a monogenean gill parasite Gastrocotyle indica has been observed in the C. kalla size groups 2.0 to 3.9 cm or 16.0 to 17.9 cm; however, the maximum specific density of 10.9 parasite/infested fish was observed in the size group 14.0 to 15.9 cm. Small fish (2.0 to 3.9 cm) carry only larvae (58/100 fish); larger hosts (4.0 to 5.9 cm) larvae (45/100 fish) and juveniles (8/100 fish); individuals of the 6.0 to 15.9 cm size group harbour larval, juvenile and adult stages of G. indica. Fishes of more than 16 cm carry only adult parasites. The level of parasitization is higher on the male hosts (30% incidence; 5 parasites/infested male) than on the females (25% incidence; 4 parasites/infested female). The highest incidences of larval, juvenile and adult G. indica occur in September, February, and May, respectively; the parasite seems to live for 1 year. The host requires a period of about 8 months to acquire immunity against infestation by G. indica or copepod parasites.     

Biocosmetics: technological advances and future outlook

Environmental Science and Pollution Research - The paper provides an overview of biocosmetics, which has tremendous potential for growth and is attracting huge business opportunities. It emphasizes...     

Development of a method for bacteria and virus recovery from heating, ventilation, and air conditioning (HVAC) filters

The aim of the work presented here is to study the effectiveness of building air handling units (AHUs) in serving as high volume sampling devices for airborne bacteria and viruses. An HVAC test facility constructed according to ASHRAE Standard 52.2-1999 was used for the controlled loading of HVAC filter media with aerosolized bacteria and virus. Nonpathogenic Bacillus subtilis var. niger was chosen as a surrogate for Bacillus anthracis. Three animal viruses; transmissible gastroenteritis virus (TGEV), avian pneumovirus (APV), and fowlpox virus were chosen as surrogates for three human viruses; SARS coronavirus, respiratory syncytial virus, and smallpox virus; respectively. These bacteria and viruses were nebulized in separate tests and injected into the test duct of the test facility upstream of a MERV 14 filter. SKC Biosamplers upstream and downstream of the test filter served as reference samplers. The collection efficiency of the filter media was calculated to be 96.5 +/- 1.5% for B. subtilis, however no collection efficiency was measured for the viruses as no live virus was ever recovered from the downstream samplers. Filter samples were cut from the test filter and eluted by hand-shaking. An extraction efficiency of 105 +/- 19% was calculated for B. subtilis. The viruses were extracted at much lower efficiencies (0.7-20%). Our results indicate that the airborne concentration of spore-forming bacteria in building AHUs may be determined by analyzing the material collected on HVAC filter media, however culture-based analytical techniques are impractical for virus recovery. Molecular-based identification techniques such as PCR could be used.     

Role of magnetite and humic acid in radionuclide migration in the environment

Sorption of ¹³⁷Cs, ⁹⁰Sr, ¹⁵⁴Eu and ¹⁴¹Ce by magnetite has been studied at varying pH (4 to 11) in the presence and absence of humic acid. The sorption studies have also been carried out at varying ionic strength (0.01 to 0.2 M NaClO₄) and humic acid concentration (2 to 20 mg/L). Percentage sorption of ¹³⁷Cs and ⁹⁰Sr was found to be pH dependent, with the sorption increasing with increasing pH of the suspension. At any pH, the percentage sorption of ⁹⁰Sr was higher than that of ¹³⁷Cs. The results have been explained in terms of the electrostatic interaction between the positively charged metal ions and the surface charge of the magnetite which becomes increasingly negative with increasing pH. On the other hand, ¹⁵⁴Eu and ¹⁴¹Ce were found to be strongly sorbed by the magnetite at all pH values, with the sorption being independent of pH. The strong sorption of trivalent and tetravalent metal ions suggests the role of complexation reactions during sorption, apart from the electrostatic interactions. However, in the case of ¹⁴¹Ce surface precipitation of Ce(III) formed by reduction of Ce(IV) in the presence of magnetite cannot be ruled out. Presence of humic acid (2 mg/L) was found to have negligible effect on sorption of all metal ions.     

Applying Fuzzy logic and the point count system to select landfill sites

The treatment of solid waste is currently one of the major environmental problems facing municipalities. Thousands of tonnes of waste are generated each day, requiring a large area for disposal purposes. It is difficult to find suitable areas for the construction of such sanitary landfills as numerous criteria must be met, and landfill sites vary considerably in terms of their sophistication. The selection criteria for landfill sites should be as simple as possible, and with this in mind, we have evaluated a large number of random cases for the suitability of the site for landfill purposes using the recently advocated fuzzy approach. Using the fuzzy classification, we have attempted to develop a simple classification which uses only certain point values for available attributes. A normalized average of such attributes based on the proposed classifier is further evaluated using additionally generated random data sets. The results appear to be encouraging and indicate that the present classifier can be used as a substitute for the fuzzy-based ranking of landfill sites.