Introduction Pesticides - biologically active substances or preparations comprising one or more substances with a wide range of biological activity, and often a specific mode of action. Active use of pesticides to control pests in agriculture and horticulture leads to their getting into rivers, lakes and groundwater. Water pollution by these substances entails great risk of poisoning organisms. Through chemical analysis pesticides or other organic pollutants found in the water samples at mkg/l. However, the use of conventional analytical techniques does not allow to determine the biological effects rendered pesticide ingredients on living organisms. Therefore, sharing and chemical analysis methods which allow to evaluate the biological effect such as toxicity tests are recommended facilities available for establishing the risk of action of pesticides.

         Today, the most promising for the assessment of the toxicity of pollutants are   bioluminescent bioassays based on glowing bacteria isolated from them and enzymatic systems.

Results At the first stage the analysis of the sensitivity of the luminescent bacteria to the action of pesticides of different nature. Figure 1 - 3 shows the dependence of the residual glow of luminescent bacteria on the concentration of pesticides. Based on these relationships were determined EC50 and EC20, the values obtained were recalculated to the concentration of the active compounds and are presented in Table 1. The figure 1-3 shows that the aqueous solutions of pesticides inhibit luminescence intensity of luminescent bacteria. The least impact on the value of the residual glow of luminescent bacteria has pesticide "Dcis"

Figure 1 - The dependence of the residual glow of luminescent bacteria on the concentration of the pesticide ("Fufanol")

 

 

Figure 2 - The dependence of the residual glow of luminescent bacteria on the concentration of the pesticide ("Decis")

 

Figure 3 - Dependence of the residual glow of luminescent bacteria on the concentration of the pesticide ("Iskra")

 

The figure 1-3 shows that the aqueous solutions of pesticides inhibit luminescence intensity of luminescent bacteria. The least impact on the value of the residual glow of luminescent bacteria has pesticide "Detcis". The sensitivity of the bacteria to the parameter EC50 3 orders of magnitude lower than the CL active ingredient pesticide "Detcis-pro" (deltamethrin) in the soil, and 2 orders of magnitude lower than the CL active ingredient pesticide "Iskra" (imidacloprid) in the soil. Thus, the sensitivity of the luminescent bacteria is not enough to test these pesticides on the MPC. It has been shown that the sensitivity of luminescent bacteria in the parameter EC20 allows to determine the presence in the sample of malathion (active ingredient of pesticide "Fufanol") at a level corresponding to its CL.

 

Table 1 - Values of toxicological parameters EC50 and the EU 20, some of the effects of pesticides on the intensity of the glow of luminescent bacteria, based on the active substance

 

Pesticid	Active substance	CL (Active substance)		ЕС50, m/l	ЕС20, m/l
		in soil, m/k	in water reservoirs, m/l
Fufanol	malathion	2,0	0,05	3,1	1,16
Decis	deltamethrin	0,01	0,01	16,7	3,34
Iskra	imidacloprid	0,04	0,03	6,3	0,42

 

As seen in Table 1, the sensitivity of bacteria to the parameter EC50 3 orders of magnitude lower than the CL active ingredient pesticide "Decis-pro" (deltamethrin) in the soil, and 2 orders of magnitude lower than the CL active ingredient pesticide "Iskra" (imidacloprid) in the soil . Thus, the sensitivity of the luminescent bacteria is not enough to test these pesticides on the CL. It has been shown that the sensitivity of luminescent bacteria in the parameter EC20 allows to determine the presence in the sample of malathion (active ingredient pesticide "Fufanol") at a level corresponding to its CL.

Thus, to increase the sensitivity of bacteria to the action of pesticides necessary to select these conditions analysis (temperature, time mode) to maximize the sensitivity of luminescent bacteria to the action of pesticides.