Genotoxic assessment of anthracene and benzo [a] pyrene to milkfish Chanos chanos

Mutagenic and genotoxic effects of polycyclic aromatic hydrocarbons, anthracene and benzo [a] pyrene (BaP), in milkfish Chanos chanos were determined using micronucleus (MN) test and comet assay (CA). Distinct mean frequencies of nuclear abnormalities such as MNs; binucleated micronuclei, nuclear bud, and fragmented apoptotic cells were measured. Significant increase in DNA damage with five classes of damage level was observed and expressed in terms of arbitrary unit (AU). Mean frequencies of total nuclear abnormalities were 0.5?±?0.25 cells in control; 0.67?±?0.33 cells in solvent control; 70?±?9.60 cells in 0.176?mg?L^?1 anthracene, and 91.83?±?6.25 cells in 0.031?mg?L^?1 BaP. The greatest DNA damage of 170AU was observed in 0.176?mg?L^?1 anthracene-exposed group and 182AU was observed in 0.031?mg?L^?1 BaP-treated fish. This study confirmed that the CA and MN assays are useful tools in determining potential genotoxicity of water pollutants and might be appropriate as a part of monitoring program.     

Carbon isotopic and biochemical fingerprints of sedimentary organic matter in lower Narmada and Tapi rivers,north-west coast of India

Sources of organic matter (OM) in lower Narmada and Tapi river-estuaries were examined using organic carbon to nitrogen ratio (C_org/N), stable carbon isotope ratio (δ¹³C_org) and lignin phenol biomarkers. The signature of lower C_org (av. 0.50%) and higher δ¹³C_org (av. –20.3‰) in Narmada and, higher C_org (av. 0.85%) and lower δ¹³C_org (av. –22.8‰) in Tapi highlight the difference in OM characteristics of both systems, nevertheless they flow adjacent to each other. The OM in Tapi was predominated by fresh plant tissues, as indicated by higher Λ8?=?1.2–3.2?mg/100?mg C_org, lower Ad/Al_v?=?0.22–0.46 and lower LPVI?=?17–23. The plant OM present in the sediments of Narmada was previously degraded and mixed with soil. The OM contribution from algae was restricted to estuarine stations in both the rivers, which was ～50% in Narmada and ～35% in Tapi. The contribution of OM from fresh vascular plant was higher (20% to 63%) in Tapi than Narmada (2% to 35%). This study illustrated the benefits of using lignin phenols along with C_org/N and δ¹³C_org to identify the potential OM sources in two large river–estuary systems of India, which highlighted the complex interaction of natural and anthropogenic processes acted on the terrestrial OM compositions.     

Induction of micronuclei in tadpoles of Odontophrynus americanus (Amphibia: Leptodactylidae) by the pyrethroid insecticide cypermethrin

Cypermethrin (CY) is an active cyano pyrethroid effective against a wide range of pests encountered in agriculture and forestry. Although CY is not mutagenic in in vitro assays for gene mutation, in vivo assays showed conflicting results. In vivo genotoxicity of the synthetic pyrethroid CY in erythrocytes of Odontophrynus americanus tadpoles was examined. The frequency of micronuclei (MN) was recorded in blood smears obtained from tadpoles exposed in vivo to four different nominal concentrations 5, 10, 20 or 40?µg?L^?1 of the compound and fixed at two sampling times 48 and 96?h. As a positive control larvae were exposed to 40?mg?L^?1 of cyclophosphamide (CP). Tadpoles exposed to all CY treatments showed a significant increase in single small MN compared to the negative control group after 48?h and at 5 and 10?µg?L^?1 of CY at 96?h. Results obtained here demonstrated the genotoxic effects of the commercial formulation CY in the anuran larvae analyzed. Thus, data suggest that measurements of MN and other erythrocytes morphological aberrations performed in circulating blood samples of O. americanus tadpoles is a method for detecting cytogenetic damage in other native species.     

Evaluation and remediation of organics,nutrients and heavy metals in landfill leachate – a case study in Beijing

Leachate pollution in landfill sites is a major source of environmental concern. This study evaluates organics, nutrients and heavy metals in a landfill site in Beijing, and introduces a method combining coagulation–flocculation with filtration for the advanced treatment of leachate. The results confirm that COD_Cr, TN, NH₄⁺ ? N, TP, Mn and As in leachate treated by an anaeobic–oxic biological method are unable to meet discharge or surface water quality standards. When treated with coagulation–flocculation combined with filtration under optimal conditions (cationic polyacrylamide dosage of 8.0 mg/L; polyaluminium chloride dosage of 350 mg/L; 0.4–0.6 mm ceramsite media in the filtration process), the residual NH₄⁺? N, TN, Mn and As in the leachate meet the maximum allowed values for landfill leachate discharge or surface water quality standards in China; the exceptions are chemical oxygen demand and total phosphorus. Leachate treatment processes could be further strengthened or improved.     

Sewage fluxes and seasonal dynamics of physicochemical characteristics of the Bhagirathi-Hooghly River from the lower stretch of River Ganges,India

ABSTRACT

To understand the temporal variations of the physicochemical characteristics of the Bhagirathi-Hooghly River (BHR), three locations representing three districts of West Bengal were selected. The material fluxes from 34 drains during pre-monsoon season was quantified. The analysis of variance (ANOVA) revealed that no significant spatial variations were observed for the physicochemical parameters, whereas seasonal variations were significant. The mean discharge was found to be highest (247.2?×?10³?m³?d^?1) in the midstream drains. Highest mean concentrations of dissolved oxygen (DO) (7.35?mg?L^?1) and nitrate (0.81?mg?L ^?1) were observed during the post-monsoon season followed by the monsoon and pre-monsoon. According to the BIS, WHO and the European standard of water quality (pH, 6.5–8.5; Nitrate, 0–2.5?mg?L^?1;DO, ≥5?mg?L^?1), the results of the respective parameters revealed the BHR system is maintained at high to good water quality, meaning that the BHR system is slightly altered from its pristine environment. The mean concentrations of biological and chemical oxygen demands were found to be high during the monsoon season, revealing that a large quantity of refractory organic matter is transported to the eastern Bay of Bengal from the Ganges.     

Phytoextraction of lead and its relationship with histidine in six plant species using ICP-MS and HPLC-MS

High-performance liquid chromatography-mass spectrometry and inductively coupled plasma mass spectrometer (ICP-MS) methods were used for determination of histidine and lead in leaves of six plant species taken from industrial areas, including Gaziantep and Bursa cities, Turkey. For extraction of histidine from plant samples, ultrapure water was used at 90°C for 30?min. Using optimum conditions of 0.2?mL?min^?1, 70?V, 15?µL and 20°C, concentrations of histidine (in mg?kg^?1) were found to be between 2 and 9 for Morus L., 6 and 13 for Robinia pseudoacacio L., 2 and 10 for Populous nigra L., 3 and 10 for Thuja, 1 and 11 for Cupressus arizonica and 4 for Cedrus libani. Concentrations of lead were in the ranges of 4–378?mg?kg^?1 for Morus L., 1–122?mg?kg^?1 for R. pseudoacacio L., 1–14?mg?kg^?1 for P. nigra L., 1.6–224?mg?kg^?1 for Thuja (Cupressaceae), 1.5–57?mg?kg^?1 for C. arizonica and 1.8?mg?kg^?1 for C. libani. Related with correlation coefficient, significant linear correlation for Thuja (Cupressaceae) (r?=?0.81) and insignificant linear correlation for P. nigra L. (r?=?0.50) were seen. Further, the leaves of Morus L., Thuja and R. pseudoacacio L. have a potential as biomonitor and/or hyperaccumulator for Pb because the rates of their maximum/minimum concentrations were found higher than 90.     

Determination of metals in printed wiring boards of waste mobile phones

Metal contents of waste mobile phones represent a major environmental risk, especially considering the adoption of inappropriate management options in developing countries including open burning and disposal into surface water bodies. In this study the metal contents of mobile phone printed wiring board (PWB) samples were assessed. Sixty-two waste mobile phones of 15 brands were collected, dismantled, and their PWB samples were analyzed for Cu, Pb, Ag and Cd. The metal concentrations in the samples varied widely between and within brands. Among these metals, Cu and Pb were found to be at very high concentrations. The range (mean?±?SD) of Cu and Pb concentrations were 94.1–532?g?kg^?1 (250?±?92.3?g?kg^?1) and 7.0–46.2?g?kg^?1 (20.1?±?8.4?g?kg^?1), respectively. All Cu and Pb concentrations exceeded toxicity threshold limit concentration (TTLC) regulatory limits used in characterizing wastes as hazardous in the state of California, USA. The mean Cu and Pb concentrations exceeded the corresponding TTLC limits by factors of 100 and 20, respectively. The Ag and Cd concentrations were in the range 59.4–759?mg?kg^?1 (mean 227?±?104?mg?kg^?1) and ND – 15.6?mg?kg^?1 (2.1?±?3.3?mg?kg^?1), respectively.     

Pollution of hazardous substances in industrial construction and demolition wastes and their multi-path risk within an abandoned pesticide manufacturing plant

Exploration of heavy metals and organic pollutants, their leaching capacity along with health and environmental risks in contaminated industrial construction and demolition waste (ICDW) within a pesticide manufacturing plant were investigated. A maximum content of 90.8 mg?kg^–1 Cd was found present in the wastes, which might originate from phosphorus rocks and industrial sulfuric acid used in pesticide production processes. An average concentration of 979.8 mg?kg^–1 dichlorovos and other 11 organophosphorus pesticide were also detected. Relatively high leaching rates of around 4.14‰were obtained from laboratory simulated ICDW using both glacial acetic acid-sodium hydroxide and deionized water. Pesticide pollutants had the strongest tendency to retaining on dry bricks (leaching rate 1.68‰) compared to mortar-coatings, etc. due to their different physical characteristics and octanol-water partioning coefficient. Mobility of pesticide from on-site ICDW by water was spatially correlated to waste types, process sections and human activities, with a flux of leaching rate between 5.9‰ to 27.4%. Risk-based corrective action (RBCA) model was used to simulate the risk of contaminated ICDW debris randomly scattered. Oral and dermal ingestion amount by local workers was 9.8 × 10^–3 and 1.9 × 10^–2 mg?(kg?d)^–1, respectively. Potential leaching risk to aquatic systems exceeded the limit for nearly 75% waste. Environmental and health risk exceedance was found in most ICDW, while the risk value of the most severely contaminated brick waste was 660 times beyond critical level. Implications for waste management involving construction and deconstruction work, waste transferring and regulation supplying were also provided.

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Change in genotoxicity of wastewater during chlorine dioxide and chlorine disinfections and the influence of ammonia nitrogen

The effects of chlorine dioxide and chlorine disinfections on the genotoxicity of different biologically treated sewage wastewater samples were studied by umu-test. The experiment results showed that when chlorine dioxide dosage was increased from 0 to 30 mg/L, the genotoxicity of wastewater first decreased rapidly and then tended to be stable, while when the chlorine dosage was increased from 0 to 30 mg/L, the genotoxicity of wastewater changed diversely for different samples. It was then found that ammonia nitrogen did not affect the change of genotoxicity during chlorine dioxide disinfection of wastewater, while it greatly affected the change of genotoxicity during chlorine disinfection of wastewater. When the concentration of ammonia nitrogen was low (< 10–20 mg/L), the genotoxicity of wastewater decreased after chlorine disinfection, and when the concentration of ammonia nitrogen was high (> 10–20 mg/L), the genotoxicity of wastewater increased after chlorine disinfection.     

In situ evaluation of the genotoxic potential of the river Nile: I. Micronucleus and nuclear lesion tests of erythrocytes of Oreochromis niloticus niloticus (Linnaeus, 1758) and Clarias gariepinus (Burchell, 1822)

This study aimed to investigate the genotoxic potential of chemicals present along the course of the river Nile using frequencies of micronuclei (MN) and nuclear lesions (NL) in erythrocytes of Nile tilapia Oreochromis niloticus niloticus and African catfish Clarias gariepinus, as biomarkers. Results showed that most of the physicochemical parameters detected and heavy metal concentrations were significantly higher in the water collected from the estuaries of the river Nile compared to other sites of the upper Nile. The frequencies of MN and NL in peripheral blood erythrocytes of Nile tilapia and African catfish were significantly higher in estuary sites in Damietta and Rosetta compared to upper sites. The lowest level of genotoxicity was observed at two sites (Aswan and Kena), considered to be less contaminated. Our results suggested that higher frequencies of MN and NL determined at Damietta and Rosetta sites may be indicative of damage produced by pollutants in these areas. The most remarkable result was that MN and NL frequencies appear to be strongly related to water quality at different sites examined, indicating that MN frequencies may serve as a reliable biomarker for testing genotoxicity in situ. The positive correlation between MN and NL induction suggested that NL may be a useful complementary assay for genotoxicity analyses when fish are used as experimental animals. It was also found that seasonal variations in MN and NL frequencies might contribute to a better understanding of genotoxic responses in the field. The use of fish as indicator organisms for monitoring the presence of genotoxic-inducing contaminants in the environment seemed justified because the effects of exposure to a “complex mixture” such as river water were obtained. Nile tilapia appears to be a more suitable bioindicator species than African catfish in studying genotoxic chemical pollution in the river Nile attributed to a higher sensitivity.     

Bioreduction of hexavalent chromium by Exiguobacterium indicum strain MW1 isolated from marine water of Paradip Port,Odisha, India

Hexavalent chromium-tolerant (1500?mg/L) bacterium MW1 was isolated from harbour water of Paradip Port and evaluated for Cr(VI) reduction potential. The isolate was identified as Exiguobacterium indicum by biochemical and 16S rRNA gene sequence methods. Salt tolerance of the bacterium was evaluated in a wide range of NaCl concentrations (0.5–13%, w/v). The Cr(VI) reduction of the strain was evaluated and optimised with varied Cr(VI) concentrations (100–1000?mg/L), pH (5.0–9.0), temperature (30–40°C) and shaking velocity (100–150?rpm) in two different minimal media (M9 and Acetate). Under optimised conditions, after 192?h of incubation nearly 92%, 50% and 46% reduction in the M9 minimal medium and 91%, 47% and 40% reduction in the acetate minimal medium were observed for 100, 500 and 1000?mg/L of Cr(VI), respectively. The exponential rate equation for Cr(VI) reduction yielded higher rate constant value, that is, 1.27?×?10^?2?h^?1 (M9) and 1.17?×?10^?2?h^?1 (Acetate) in case of 100?mg/L and became lower for 500 and 1000?mg/L Cr(VI) concentrations. Further, the association of bacterial cells with reduced product was ascertained by Fourier transform infrared spectrometer, UV–Vis–DRS and field-emission scanning electron microscope–energy-dispersive X-ray analyses. The above study suggests that the higher reducing ability of the marine bacterium E. indicum MW1 will be suitable for Cr(VI) reduction from saline effluents.     

Effects of nitrogen addition on the growth of the salt marsh grassElymus athericus

Effects of nitrogen addition on the growth of the salt marsh grassElymus athericus were studied under greenhouse conditions. The addition of inorganic nitrogen (in the form of nitrate or ammonium and ranging from 0–24 g N/m²) stimulated the growth ofElymus athericus at the highest addition. Addition of nitrogen led to an increase of the soil nitrate concentrations both in the nitrate and ammonium treated soil in the first period of the experiment, whereas no differences were present at the end of the experiment. Ammonium in the ammonium treatments was transformed to nitrate within 15 days. In another experiment the values of the stable isotope nitrogen-15—expressed as δ¹⁵N-in nitrogen compounds used as fertilizer, in salt marsh soil and ofElymus athericus were measured. The δ¹⁵N of the N-compounds added (between ?3.2 and +2.6‰) were lower than the soil (ca.+10‰) and plants (ca.+8‰). During growth in water culture the δ¹⁵N of the leaves, stems and roots ofElymus athericus decreased from +9‰ to ?1‰. The latter value was close to the °¹⁵N of the N-compounds used in the water solution. Addition of N-compounds in soil culture, however, did not lead to such a decrease of the °¹⁵N ofElymus athericus. The difference in δ¹⁵N between soil nitrogen and the N-compounds added may be too small to be used successfully in ecological studies of nitrogen fluxes in the salt marsh environment.     

Acute toxicity of ammonia to a freshwater teleost,Labeo bata larvae

Ammonia toxicity tests were performed with Labeo bata (bata) larvae of three different size groups. One hundred percent survival of larvae (500.0?±?4.0?mg) was recorded when exposed to ammonia concentrations of 1.0–13.56?mg?L^?1 at 96?h of exposure. Bata larvae exposed to ammonia concentrations of 15.8–25?mg?L^?1 showed 10–74% mortalities. The 96?h LC₅₀ value for 200 (±5), 250 (±2) and 500 (±4) mg bata larvae were 11.5, 16.8 and 22.5?mg?L^?1 un-ionised ammonia concentrations, respectively. When fish were exposed to different doses of ammonia, behavioural changes immediately occurred even at the lowest dose. At first, the fish became hyperexcitable, the skin darkened and they showed an increased ventilation frequency, fish behaviour became normal, 24?h after exposure. A 96?h LC₅₀ value of un-ionised ammonia showed direct relationship with the increasing size of bata larvae.     

Effect of salinity on hypoxia tolerance of resting green crabs, Carcinus maenas, after feeding

Mechanisms that can influence the tolerance of hypoxia in brackish waters were studied in resting and fed crabs, Carcinus maenas, at 15?°C. Mortality, blood oxygenation, acid-base status and lactate concentration were analysed in fed crabs held in full-strength normoxic seawater (32.5‰?S) and then transferred for 24?h to a partial pressure of oxygen (P_o2) of 3?kPa (1.4?mg?l^?1) and various salinities (17, 12.5, 10, 8‰?S). At salinity levels >10‰, fed crabs tolerated P_o2 values as low as 3?kPa in the ambient water and 0.5?kPa in their arterial blood for 24?h without switching to anaerobic metabolism. Only below 10‰?S did their blood-lactate content rise, leading to their death despite the fact that their blood O₂-content was twice the control value measured in full-strength normoxic seawater and their blood P_o2 did not decrease below values recorded at higher salinity levels. Addition of CO₂ to 8‰?S water (CO₂ partial pressure increasing from 0.1 to 0.3?kPa) decreased blood-lactate production and mortality, suggesting that at 10‰?S impairment of the O₂ supply is limited by an excessive blood O₂-affinity. The results are discussed in terms of the distribution (?10‰?S) of C. maenas along salinity gradients in estuaries and bays.     

13C isotope evidence for photochemical production of atmospheric formaldehyde, acetaldehyde, and acetone pollutants in Guangzhou

Ambient formaldehyde, acetaldehyde, and acetone are harmful air pollutants with potential carcinogenic effects on human health. They are considered as important photochemical products from photo-oxidation of atmospheric hydrocarbons. However, little is known on the effet of photodegradation of air pollutants on δ¹³C values. Here, we report the first ¹³C isotope evidence for the photochemical production of ambient formaldehyde, acetaldehyde, and acetone. Air samples were collected each day during early morning, noon, early afternoon, and late afternoon on 17–19 September 2008 in Guangzhou by drawing air through 2,4-dinitrophenylhydrazine-coated cartridges. The samples were analyzed using high-performance liquid chromatography for concentration analysis and then using gas chromatography-combustion-isotope ratio mass spectrometry for δ¹³C analysis. Our results show that ambient formaldehyde, acetaldehyde, and acetone were enriched by 1–5 ‰ in ¹³C in the early afternoon relative to other sampling durations, and they also exhibited the highest concentrations in the early afternoon. Measured δ¹³C values of formaldehyde, acetaldehyde, and acetone were in the range from ?37.15 to ?29.01 ‰. The observed enrichment in ¹³C implied important photochemical production together with the highest concentrations in the early afternoon. Especially, measured δ¹³C range from ?37.15 to ?29.01 ‰ was in accordance with forecasted δ¹³C range from ?43 to ?28 ‰ based on the mass balance in ¹³C between the carbonyls and its major hydrocarbon precursors, providing important ¹³C isotope evidence for the photochemical production of ambient formaldehyde, acetaldehyde, and acetone.     

Production primaire au niveau de la thermocline en zone néritique de Méditerranée Nord-Occidentale

Vertical profiles of physical, chemical and phytoplanktonic parameters are described, at the level of the thermocline, in the area of Banyuls-sur-Mer, France. The results show that the thermocline divides two masses of water: (1) Mediterranean surface water with low nutrient concentrations and a salinity below 38.00 ‰; (2) deep, nutrient-rich upwelled water (N?NO₃ >3 μat-g·l^-1, P?PO₄>0.3 μat-g·l^-1, >38.30 ‰ S), which comes from the upper limit of the Mediterranean intermediate water, usually located at the 200 m level. Consequently, conditions are suitable for high production rates at the bottom of the thermocline, where Chl a is above 0.5 mg·m^-3; dominant species are Nitzschia delicatissima and N. pungens. A diagram is presented explaining the different effects of the pycnoclines on primary production: eutrophication at the pycnocline levels is the result of passive accumulation of phytoplankton and organic matter during sedimentation, and/or of reduced diffusion of nutrients from deep waters towards the surface.     

Quality of tube well water intended for irrigation and human consumption with special emphasis on arsenic contamination at the area of Punjab,Pakistan

In the present study, the tube well water quality and the associated health risks, emphasizing on arsenic contamination, were investigated in rural and urban samples from Tehsil Mailsi located in Punjab, Pakistan. Arsenic concentrations (μg/L) were ranged from 12 to 448.5 and which exceeded the WHO recommended limit (10 μg/L) in all cases. The calculated average daily dose (3.3 × 10^?0.4 to 1.2 × 10^?0.2 mg/kg day) and hazard quotient (1.1–40) reflected the potential health risk to local population due to tube well water consumption as drinking purpose. Sodium percent (Na%), sodium absorption ratio, residual sodium carbonate, Kelly’s index and magnesium absorption ratio were also determined to assess the suitability of tube well water for irrigation purpose. The resulting piper plot revealed the Na–Ca–HCO₃ type water chemistry of the area and generally alkaline environment. The spatial distribution of arsenic in the tube well waters pinpoints the significant contribution of anthropogenic activities to arsenic pollution. Nevertheless, different statistical tools, including principal component analysis, hierarchical cluster analysis and correlation matrices, revealed the contribution of both natural and anthropogenic activities and alkaline type of aquifers toward the high level of arsenic contamination.     

典型酚类化合物对土壤跳虫的慢性毒性

以跳虫Folsomia candida为受试物种,基于其28 d繁殖试验评价了12种典型酚类化合物的慢性毒性效应。结果表明,在所设浓度范围内,除间苯二酚外的其他酚类对跳虫繁殖均存在不同程度的抑制效应。氯酚类对跳虫慢性毒性最大,2,4-二氯酚、2-氯酚、2,4,6-三氯酚对跳虫繁殖毒性的EC50分别为5.94、10.2、19.7 mg·kg-1;其次为烷基酚类,2,4-二甲基酚、3-甲基酚、壬基酚对跳虫繁殖毒性的EC50分别为21.7、35.1、50.5 mg·kg-1。苯酚的毒性较上述烷基酚低,EC50值为71.7 mg·kg-1。其他取代酚—包括2-萘酚、4-硝基酚、邻苯二酚对跳虫繁殖的EC50分别为95.4、133、306 mg·kg-1。双酚A仅在最高浓度(500 mg·kg-1)处理下对跳虫繁殖有显著影响。     

Reduction of hexavalent chromium using fungi and bacteria isolated from contaminated soil and water samples

The reductive adsorption of hexavalent chromium (Cr⁶⁺) using six indigenous microorganisms isolated from contaminated soil and water samples was investigated. Quantification of Cr⁶⁺ reduction was determined using the 1,5-diphenylcarbazide method followed measuring the absorbance at OD₅₄₀. Bacterial isolates identified as Klebsiella pneumoniae, Bacillus firmus and Mycobacterium sp. were capable of absorbing Cr⁶⁺ efficiently into their biomass, whereas the fungal isolates, Aspergillus flavus, Aspergillus sp. and A. niger were capable of transforming Cr⁶⁺ to Cr³⁺ relative to cell-wall-binding properties. Infrared spectral analysis of functional groups showed that ?OH, ?NH₂ and C?O with conjugated ?NH were the binding groups responsible for adsorption of Cr⁶⁺ within the biomass of isolates. The data highlight the promising biotechnological application of these isolates in removing carcinogenic and mutagenic Cr⁶⁺ from contaminated ecosystems.     

Protective effect of kombucha mushroom (KM) tea on phenol-induced cytotoxicity in albino mice

The present study was carried out to evaluate the protective role of kombucha mushroom (KM) tea on cytotoxicity induced by phenol (PHE) in mice. We used weight gain and micronucleus (MN) frequency as indicators of cytotoxicity and supported these parameters with pathological findings. The animals were randomly divided into seven groups: (Group I) only tap water (Group II) 1000 microl kg(-1) b. wt KM-tea, (Group III) 35 mg kg(-1) body wt. PHE (Group IV) 35 mg kg(-1) body wt. PHE + 250 microl kg(-1) b. wt KM-tea (Group V) 35 mg kg(-1) b. wt PHE + 500 microl kg(-1) b. wt KM-tea (Group VI) 35 mg kg(-1) b. wt PHE + 750 microl kg(-1) b. wt KM-tea, (Group VII) 35 mg kg(-1) b. wt PHE + 1000 microl kg(-1) b. wt KM-tea, for 20 consecutive days by oral gavage. The results indicated that all KM-tea supplemented mice showed a lower MN frequency than erythrocytes in only PHE-treated group. There was an observable regression on account of lesions in tissues of mice supplemented with different doses of KM-tea in histopathological observations. In conclusion, the KM-tea supplementation decreases cytotoxicity induced by PHE and its protective role is dose-dependent.