Pol. J. Environ. Stud. Vol. 20, No. 5 (2011), 1259-1265 Original Research Krzna River Basin Pollution by Chosen Chloroorganic Pesticides Marcin Nowik1*, Andrzej L. Dawidowicz2 1County Sanitary and Epidemiological Station in Biała Podlaska, Kopernika 7, 21-500 Biała Podlaska, Poland 2Faculty of Chemistry, Maria Curie Sklodowska University, Marii Curie Sklodowskiej 3, 20-031 Lublin, Poland Received: 15 November 2010 Accepted: 15 April 2011 Abstract Chloroorganic pesticides belong to a group of compounds whose specific characteristics classify them as one of the most dangerous for the environment. Although the use of chloroorganic pesticides was banned in Poland and other countries many years ago, regular monitoring of these compounds in the natural environ- ment is still required due to their exceptional toxicity and significant durability. Our paper presents and dis- cusses the concentration levels of selected chloroorganic pesticides [p, p'-DDT and its metabolites (p, p'-DDE, p, p'-DDD), HCH isomers (α-HCH, γ-HCH), heptachlor, epoxide heptachlor, hexachlorobenzene (HCB), endrin, aldrin, and dieldrin] in soil, river sediment, and water samples taken from the Krzna River, the biggest left-hand tributary of the Bug River, and from its bank. The results indicate that the concentrations chloroor- ganic pesticides in the examined samples are generally low. Some increase of the accepted pesticide concen- tration level is observed in the vicinity of Rzeczyca village, which points to the necessity of continuous mon- itoring of this region. Keywords: chloroorganic pesticides, Krzna River basin pollution Introduction tachlor, aldrin, and dieldrin are the most representative in this group. These chlorohydrocarbons are still used in some The term pesticides, proposed by The Food and countries to destroy insects in fields, forests and buildings, Agriculture Organization of the United Nations, is applied to as well as insect parasites of people and animals. They dif- a wide spectrum of natural and synthetic compounds used fer in respect to the structure and the chlorine level, which against the action and activity of organisms that are dangerous influences their different toxic and physico-chemical prop- for human beings, man-made, and man-used products [1]. erties [2]. Among the large number of pesticides are insecticides named It should be stated that chloroorganic pesticides in chloroorganic pesticides that deserve special attention. p,p’- Poland were replaced a long time ago by other groups of DDT (1,1,1-trichloro-2,2-di(4-chlorophenyl)ethane) and its compounds of similar effectiveness, but that are much more metabolites (p,p’-DDE – 1,1-bis-(4-chlorophenyl)- 2,2- easily degradable (e.g. phosphoroogranic insecticides). In dichloroethene), p,p’-DDD – 1-chloro-4-[2,2-dichloro-1- spite of this fact, levels of chloroorganic pesticides are still (4-chlorophenyl) ethyl]benzene), hexachlorocyclohexane continuously monitored throughout the country, due to the (HCH) isomers (α-HCH, β-HCH, γ-HCH, δ-HCH), hep- danger they pose. A characteristic feature of chloroorganic pesticides is *e-mail: [email protected] the long period of their degradation, both in the natural 1260 Nowik M., Dawidowicz A. L. environment and in living organisms. This results mainly Krzna, the largest left tributary of the Bug, flows from their resistance to enzymatic transformation. through central-eastern Poland (Fig. 1). It is 125 kilometers Chloroorganic pesticides are hardly metabolized and there- long and has a mean discharge of 10.5 m3/s at its mouth fore are only slowly removed from the organism. They tend [16]. The basin of thr Krzna (about 3,300 km2) is a typical to store up in the cells of organisms on all the subsequent farming area with numerous small farms inhabited by a levels of the food chain [3]. Many of them exhibit carcino- populace of ca. 340,000. The existence of farms in the area genic, mutagenic, and teratogenic activity (i.e. they may be has a significant influence on the pesticide contamination dangerous to embryos and fetuses). They can cause disor- level in the area, as most pesticides in the soil, sediment, ders of the nervous system, cancer, shortness of breath, and and surface waters come from farming. The considerable damage bone marrow [4-6]. Another characteristic of pesti- fragmentation of the farm area limits the possibilities of cides is their mobility in the environment, e.g. in a soil [7] thorough control of plant and animal protection agents or from soil to crops [8]. Pesticides penetrate the atmos- applied in the area. The Krzna flows through several towns, phere relatively easily due to their high vapor pressure [9]. including: Biała Podlaska, Łuków, and Międzyrzec Pesticides applied in tropical climates are transported with Podlaski, where it is a source of drinking water. Some frag- the air into the cooler regions of the world [10, 11]. ments of the river run have been included in natural reserve Before revealing negative activity of chloroorganic pes- areas. It is worth noting additionally that in Kaliłów and ticides, their production was massive and they were widely Adamki, villages located in the Krzna basin, are the waste applied in many countries. For example, ca. 75,000 tons of repositories containing traces of chloroorganic pesticides. p,p’-DDT was produced by Polish factories in the period The last fact additionally support the necessity of the Krzna 1949-78 [12]. Despite the straightforward ban concerning basin control with respect to the pesticide level, despite the the use and production of chloroorganic pesticides [13], fact that repositories were cleared in 2001. It is worth men- they are still applied in many developing countries and their tioning that the water in the Krzna is systematically moni- presence is found in foods of animal origin [14]. The tored [17]; however, no detailed analysis for chloroorganic extremely toxic properties of chloroorganic pesticides and pesticides have yet been performed [18-20]. their considerable durability make necessary regular moni- toring of these compounds, even today [15]. Experimental The Research Area Validation of Analytical Procedure Applied for the Estimation of Chloroorganic Pesticides Our paper presents and discusses the results of quantifi- in Soil, Sediment, and Water cation analysis of typical chloroorganic pesticides such as p,p’-DDT and its metabolites (p,p’-DDE, p,p’-DDD), HCH The procedure combining SPE technique (employing isomers (α-HCH, γ-HCH), heptachlor, heptachlor epoxide, octadecyl-modified silica bed) with further analysis of SPE hexachlorobenzene (HCB), endrin, aldrin, and dieldrin in extract by means of gas chromatography with ECD detec- soil, sediment, and water sampled from the Krzna River tion is one of the most popular methods applied for the and its banks. analysis of chloroorganic pesticides [21-24]. This proce- Fig. 1. Krzna River and points of sample collection. Krzna River Basin Pollution... 1261 dure was applied for analysis of water, soil, and sediment Soil Samples samples from the Krzna basin. In order to estimate the reli- ability of results obtained in our laboratory, a validation of Soil samples were collected by hand using a metal spat- the procedure was performed [25, 26]. Such parameters as ula at a depth of 0-15 cm and 1 m from the shore. They detection limit, the quantification limit, the range of were initially purified from larger contaminants (stones, method, method sensitivity, linearity, recovery, uncertainty, plant parts) and transported to the laboratory in glass con- and precision in repetitive conditions were evaluated. All tainers. Collected samples were dried at about 100ºC to these elements were calculated separately for each pesticide constant weight. The dried soil samples were crushed in a and for each matrix (soil, water, sediment) following the mortar and fractionated using sieves. A grain fraction less same sample preparation procedure as that described than 2 mm was used in the studies. The samples prepared below. Certified reference materials (CRM) were used, as in the above way were stored in glass containers at +4ºC. well as reference materials prepared on the basis of pesti- Sample preparation procedure was as follows: to 5 g of cide matrices (RM) relevant to the analyzed samples. The analyzed soil 50 μl solution of tetrachloro-m-xylene (LGC parameters established in the process of validation are pre- Standards) in acetone (J.T. Baker) was added as an internal sented in Table 1. standard (50 ng/ml). The sample was then shaken for 30 min The limit of detection (LOD) and the limit of quantifi- with 10 ml of methanol (J.T. Baker). The resulting extract cation (LOQ) involved measurements of 10 independent was filtered into a 50 ml volumetric flask using the 3 h filter samples, where the level of the analyzed compound was (Filtrak). Residual sludge was poured again with a new por- close to the expected limit of detection. The results thus tion of methanol, and extraction was repeated twice, each acquired were subjected to the Q-Dixon Test for identifica- time pouring the extract into the flask so that each sample of tion and rejection of outliers, and then standard deviation the soil was extracted three times. The flask with the com- was calculated for them. The triple standard deviation and bined extracts was filled up to its volume with methanol. the six-times standard deviation were accepted for the limit The resulting solution was subjected to SPE procedure using of detection and for the limit of quantification, respectively. the SPE 12G chamber (J.T. Baker) and SPE column filled The method range, its linearity, and the method sensi- with 500 mg octadecyl-bonded silica gel (J.T. Baker) previ- tivity were established on the basis of the calibration curve ously conditioned according to manufacturer's instructions. and curve equation. Measurements of solution matrices on The SPE column was next dried for 30 min, sucking the air three levels of concentration were performed five times.