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Laboratory evaluation was made to access the seasonal variations in abiotic environmental factors temperature, pH, dissolved oxygen, carbon dioxide, electrical conductivity and ferulic acid toxicity in snail-attractant pellets (SAP) against the intermediate host snail Lymnaea acuminata in each month of the years 2010 and 2011. On the basis of a 24-h toxicity assay, it was noted that lethal concentration values of 4.03, 3.73% and 4.45% in SAP containing starch and 4.16, 4.23% and 4.29% in SAP containing proline during the months of May, June and September, respectively, were most effective in killing the snails, while SAP containing starch/proline + ferulic acid was least effective in the month of January/February (24-h lethal concentration value was 7.67%/7.63% in SAP). There was a significant positive correlation between lethal concentration value of ferulic acid containing SAP and levels of dissolved O2 /pH of water in corresponding months. On the contrary, a negative correlation was observed between lethal concentration value and dissolved CO2 /temperature of test water in the same months. To ascertain that such a relationship between toxicity and abiotic factors is not co-incidental, the nervous tissue of treated (40% and 80% of 24-h lethal concentration value) and control group of snails was assayed for the activity of acetylcholinesterase (AChE) in each of the 12 months of the same year. There was a maximum inhibition of 58.43% of AChE, in snails exposed to 80% of the 24-h lethal concentration value of ferulic acid + starch in the month of May. This work shows conclusively that the best time to control snail population with SAP containing ferulic acid is during the months of May, June and September.

Objective: The present work investigates the metal uptake of the plant Ficus religiosa leaves collected from nine experimental sites in Gorakhpur, Uttar Pradesh. Materials and Methods: The concentration of lead in leaves was determined with help of atomic absorption spectrophotometer. Results: The level of the lead in leaves of Ficus religiosa was much higher than the limits recommended by World Health Organization (WHO). The bioaccumulation of lead was highest in site 2 (Gayatri nagar) i.e. 14.1 mg kg-1 dry weight of F. religiosa. To determine the relationship between the lead concentration in leaves and traffic density the Pearson's correlation analysis has been performed. Conclusion: The value of Pearson's correlation coefficient () was positive indicating that the traffic density plays an important role in the lead pollution in plants.

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