Apparent nutrient digestibility of carbohydrate (corn) in Cirrhinus mrigala under the influence of chromium chloride hexahydrate / Digestibilidade aparente de nutrientes oriundos de carboidratos (milho) em Cirrhinus mrigala sob a influência do cloreto de cromo hexa-hidratado

Abstract A feeding trial was carried out to assess the effect of dietary chromium supplementation on apparent nutrient digestibility coefficient (%) of gelatinized and non-gelatinized corn in Cirrhinus mrigala fingerlings for 90 days. Using various levels of chromium chloride hexahydrate six test diets designated as T1 (G/0.0 Cr2Cl3.6H2O mg Kg-1), T2 (NG/0.0 Cr2Cl3.6H2O mg Kg-1), T3 (G/0.2 Cr2Cl3.6H2O mg Kg-1), T4 (NG/0.2 Cr2Cl3.6H2O mg Kg-1), T5 (G/0.4 Cr2Cl3.6H2O mg Kg-1) and T6 (NG/0.4 Cr2Cl3.6H2O mg Kg-1) were prepared. Results showed highest apparent digestibility coefficient (ADC) of nutrients dry matter, crude lipid and gross energy in test diet T5 that was gelatinized and supplemented with chromium 0.4 mg/Kg while, for crude protein higher value of nutrient digestibility was recorded in T3 test diet (G/0.2 Cr2Cl3.6H2O mg/Kg). It was concluded that chromium supplementation with gelatinized corn in fish (Cirrhinus mrigala) diet can improve the nutrients digestibility more efficiently.

Resumo Um experimento referente à alimentação foi realizado para avaliar o efeito da suplementação dietética de cromo, no coeficiente de digestibilidade aparente do nutriente (%) do milho gelatinizado e não gelatinizado em alevinos de Cirrhinus mrigala por 90 dias. Usando vários níveis de cloreto de cromo hexa-hidratado, seis dietas testes foram designadas e preparadas como: T1 (G/0,0 Cr2Cl3.6H2O mg Kg-1); T2 (NG/0,0 Cr2Cl3.6H2O mg Kg-1); T3 (G/0,2 Cr2Cl3.6H2O mg Kg-1); T4 (NG/0,2 Cr2Cl3.6H2O mg Kg-1); T5 (G/0,4 Cr2Cl3.6H2O mg Kg-1) e T6 (NG/0,4 Cr2Cl3.6H2O mg Kg-1). Os resultados mostraram maior coeficiente de digestibilidade aparente (CDA) em matéria seca de nutrientes, lipídios brutos e energia bruta na dieta teste T5, que foi gelatinizada e suplementada com cromo 0,4 mg / Kg; enquanto que para a proteína bruta, foi registrada maior digestibilidade dos nutrientes na dieta teste T3 (G/0,2 Cr2Cl3.6H2O mg/Kg). Concluiu-se que a suplementação de cromo com milho gelatinizado na dieta de peixes (Cirrhinus mrigala) pôde melhorar a digestibilidade dos nutrientes de forma mais eficiente.

Germinação de Phaseolus aureus contaminados com diferentes fontes de cromo (VI) / Germination of Phaseolus aureus contaminated with different sources of chromium (VI)

O excesso de Cr nas plantas pode provocar inibição no crescimento das plantas, clorose nas folhas, desequilíbrio nutricional e alteração na germinação das sementes, sendo também altamente tóxico para humanos. Objetivou-se avaliar a germinação de sementes de feijão submetidas a diferentes fontes de Cr, em câmara germinadora durante 9 dias. As fontes de Cr utilizadas: cromato de potássio e dicromato de potássio, em 128 subamostras em soluções de concentrações crescentes de Cr (0, 5,10, 20, 45, 90, 200 e 400 mg L-1). Realizou contagem de sementes normais, anormais e mortas. Conclui-se que sementes de feijão submetidas ao dicromato de potássio germinam 47,5% em média, sem efeitos prejudiciais ao seu desenvolvimento, com apenas 0,87% de sementes anormais e 1,6% em média de sementes mortas, ambas com tolerância de até 400 mg L-1.

Desempenho e resposta imune de frangos de corte alimentados com dietas suplementadas com cromo na forma orgânica / Immune response and performance by broiler chickens dietarysupplemented with chromium in organic form

O experimento foi conduzido com o objetivo de avaliar o efeito da suplementação de cromo-orgânico, sobre o desempenho, biometria dos órgãos digestivos e linfoides, histomoformetria da bolsa cloacal e rendimento de carcaça e cortes nobres de frangos de corte de 1 a 41 dias de idade, naturalmente submetidos a estresse por calor cíclico. Foram utilizados 400 pintos de corte da linhagem Cobb, em um delineamento experimental inteiramente casualizado, com cinco tratamentos: 0; 350; 700; 1050 e 1400 ppb de cromo na ração. Os valores do índice de temperatura de globo e umidade foram respectivamente, 83,39 e 80, para fase de crescimento e terminação. A suplementação do cromo orgânico influenciou (P 0,01) de forma quadrática a conversão alimentar dos animais segundo a equação Y=1,67-0,00016x+0,00000012x² (r² 0,976), na fase de 1 a 21 dias de idade. Os níveis de suplementação do cromo orgânico proporcionaram melhor índice de eficiência produtiva e maior percentual de parênquima cortical nas aves aos 21 dias. Na fase de 1 a 41 dias de idade, verificou-se que o peso de penas foi influenciado positivamente com os níveis de cromo orgânico e que não houve efeito para o desempenho dos frangos. Conclui-se que a suplementação da ração com cromo orgânico melhora desempenho e a resposta imune de frangos de corte frente a condições de estresse por calor.

This study was conducted to evaluate the effect of adding organic chromium dietary supplementation on performance, digestiveand lymphoid organs biometry and histomorphometry of the clocal bursa and on carcass and prime cuts performance of broilersfrom 1 to 41 days old, naturally stressed by heat cyclic. We used 400 chicks Cobb, the experimental design adopted was acompletely randomized, with five treatments: 0; 350; 700; 1050 and 1400 ppb chromium in diet. The supplementation withorganic chromium influenced (p<0,01) quadratic form on alimentary conversion the animals according to the equation Y = 1.67to 0.00016 x 0.00000012 x ² (r ² 0.976) in the period 1 to 21. The levels of supplementation of organic chromium improvementproductive efficiency and percentage of cortical parenchyma of broilers to 21 days. In phase to 1 from 41 days old, it was observedimprovement the feathers weight with levels of organic chromium, and there wasn’t influence on performance of broilers. Thechromium in the organic form improves the performance of broiler chickens and immune response by broiler chickens in cyclic heat stress.

Impairment of renal structure and function following heterogeneous chemical mixture exposure in rats.

Renal structural and functional alterations following an exposure to a heterogeneous chemical mixture (HCM) of phthalic acid di butyl ester, 1, 2–dichlorobenzene, cadmium chloride and chromium trioxide, administered through oral gavage in low doses (1/100 and 1/1000 of LD50 value of individual chemical) for 60 days, followed by withdrawal till 120 days resulted in significant rise in kidney lipid peroxidation and fall in the activities of enzymatic antioxidants. However, withdrawal of HCM treatment restored most of these altered parameters. Degenerative changes in the kidney included proximal convoluted tubules devoid of brush boarder with cytoplasmic blebbing, dissolution and sloughing of nuclei. Cortical glomeruli were also affected with epithelial disintegration, pyknosis of podocyte nuclei and mesengial cell hyperplasia. The morphological alterations recovered fully in the low dose compared to the high dose treatment group.

Evaluation of RbCl and CrCl3 as markers of Triatoma brasiliensis (Hemiptera: Reduviidae) nymphs: persistence and influence of Rb and Cr on triatomine biology

In order to mark Triatoma brasiliensis, the vector of Chagas disease in Brazil, two chemical compounds, rubidium chloride (RbCl) and chromium chloride (CrCl3), were tested. First, 199 N2-N5 nymphs were fed on blood with 0.025M RbCl. Rb marker positivity ranged from 2.5 percent (N3)-70 percent (N2), with a maximum persistence of 98 days. Second, 265 N2-N5 nymphs were fed on blood containing 0.0015M CrCl3. Cr marker positivity ranged up to 93 percent (N5), with a maximum persistence of 119 days. Finally, we blood fed 213 T. brasiliensis to investigate whether CrCl3 altered the biology of this insect. The developmental time of T. brasiliensis was unaltered, but the survival of the Cr-marked group was lower than that of the control group. Differences in the mean fecundity of the control (mean of 156.1) and experimental (mean of 135.6) groups were not statistically significant and 100 percent of the egg batches of females Cr-marked as nymphs were positive. In conclusion, CrCl3 is a useful tool for marking T. brasiliensis nymphs due to its high positivity and persistence.

Effects of chromium chloride addition on coloration and mechanical properties of 3Y-TZP / 대한치과보철학회지

PURPOSE: The purpose of this study was to examine the effects of chromium chloride addition on coloration, mechanical property and microstructure of 3Y-TZP. MATERIALS AND METHODS: Chromium chloride was weighed as 0.06, 0.12, and 0.25 wt% and each measured amount was dissolved in alcohol. ZrO2 powder was mixed with each of the individual slurry to prepare chromium doped zirconia specimen. The color, physical properties and microstructure were observed after the zirconia specimen were sintered at 1450degrees C. In order to evaluate the color, spectrophotometer was used to analyze the value of L*, C*, a* and b*, after placing the specimen on a white plate, and measured according to the International Commission on Illumination (CIE) standard, Illuminant D65 and SCE system. The density was measured in the Archimedes method, while microstructures were evaluated by using the scanning electron microscopy (SEM) and XRD. Fracture toughness was calculated Vickers indentation method and indentation size was measured by using the optical microscope. The data were analyzed with 1-way ANOVA test (alpha= 0.05). The Tukey multiple comparison test was used for post hoc analysis. RESULTS: 1. Chromium chloride rendered zirconia a brownish color. While chromium chloride content was increased, the color of zirconia was changed from brownish to brownish-red. 2. Chromium chloride content was increased; density of the specimen was decreased. 3. More chromium chloride in the ratio showed increase size of grains. 4. But the addition of chromium chloride did not affect the crystal phase of zirconia, and all specimens showed tetragonal phase. 5. The chromium chloride in zirconia did not showed statistically significant difference in fracture toughness, but addition of 0.25 wt% showed a statistically significant difference (P<.05). CONCLUSION: Based on the above results, this study suggests that chromium chlorides can make colored zirconia while adding in a liquid form. The new colored zirconia showed a slight difference in color to that of the natural tooth, nevertheless this material can be used as an all ceramic core material.

[Effects of natuzyme dietary supplements on feedlot performance, feed digestibility and rumen metabolities in Varamini male lambs]

Different supplementary enzymes have used widely in diets for ruminants and non-ruminants over the past decade. The present study investigated the effect of feeding natuzyme [enzyme supplement] on feedlot performance, feed digestibility and rumen metabolites of Varamini male lambs. Twenty-four Varamini male lambs [initial body weight 22 +/- 1.5 Kg with 3 to 4 months age] used in a completely randomized design for 84 days. The lambs were randomly allocated to three rations of 1] without enzyme, control diet, 2] with 0.5 g/kg of feed natuzyme, 3] with 1 g/kg of feednatuzyme with 8 replication. Basal diet was formulated according to CNCPS for sheep. Daily dry matter intake and monthly average gain of lambs recorded and digestibility of basal diet measured with chromic oxide as external marker. At the end of examination, rumen liquid samples collected from lambs and its pH and ammonia nitrogen were measured. The results showed that diets did not make significant effect on the average daily gain, dry matter intake and feed conversion ratio in lambs. Meanwhile, digestibility of crude protein, ether extract, dry matter, organic matter, neutral detergent fiber and acid detergent fiber of basal diet, ruminal pH and ammonia nitrogen did not show difference between diets. We concluded that use of 0.5 or 1 g/kg of feed natuzyme did not make significant effect on the performance of Varamini male lambs

Factors affecting aromatization functionality of n-heptane onto Cr[2]O[3]-Al[2]O[3] catalysts doped with K[2]O

CHROMIA/ALUMINA catalysts containing 2, 4, 8, 16 and 32 mol% Cr[2] O[3]. were prepared using the co-precipitation technique. Doping of the precipitated gels with 2 mol% K[2]O was made prior to calcinations at 500, 700 and 900 [degree sign] C. The structures of the calcinations products were determined from their XRD patterns and their textural properties were determined from the adsorption of nitrogen at 77 K. The dehydrocyclization of n-heptane was carried out at 520-580[degree sign] C. using helium as a gas carrier at a rate of 20-60 ml/min, in a pulse micro-reactor directly attached to a flame ionization detector. Samples containing 2 or 4 mol% Cr[2]O[3] did not show any crystalizied chromia phase, whereas those containing higher Cr[2]O[3] content showed gamma- and/or alpha- Cr[2]O[3] depending on their chromia content and calcination temperature. The surface area decreased and the pore size increased with increase of chromia content and with the rise of the calcinations temperature. Chromia/alumina catalysts calcined at 700 [degree sign] C exhibited the highest dehydrocyclization activities compared with the corresponding catalysts calcined either at 500 at 900 [degree sign] C. The conversion of n-heptane proceeded mainly via dehydrocyclization to toluene [major] and benzene [minor], with very low yield of cracking products of C[5]-naphthenes

Solid - Solid interaction in pure and Li[2]O-doped Cr[2]O[3]/CuO System

Cr[2]O[3]/CuO systems having the formulae 0.2 Cr[2]O[3]/CuO and 0.5, Cr[2]O[3]/CuO were prepared by mixing the calculated amounts of copper nitrate trihydrate with CrO[3] dissolved in the least amount of distilled water sufficient to make pastes. The obtained pastes were dried at 100°C then calcined at 500, 700 and 900°C. The solid-solid interactions between chromium and copper oxides were investigated by using DTA and XRD techniques. The effects of Li[2]O-doping [1.5 and 4.5 mol%] of the systems investigated on solid-solid interactions taking place between Cr[2]O[3] and CuO have been also investigated. The results revealed that the investigated mixed solids [copper nitrate and CrO[3] underwent thermal decomposition at about 370°C yielding CuO and Cr[2]O[3-] Chromium oxide interacted readily with CuO producing copper chromate [CuCr[2]O[4]] at temperatures starting from 500°C. The produced phase remained thermally stable by heating at 700°C then converted into CuCrO[2] by heating at 900°C. Li[2]O-doping of the investigated system enhanced the chromate formation and hindered the reduction of some of cupric into cuprous oxides

Adsorption of anionic dyes on to waste Fe (III)/Cr (III).

Waste Fe (III)/Cr (III) hydroxide was investigated for the removal of anionic dyes, namely acid brilliant blue (acidic dye) and procion red (reactive azo dye) from aqueous solution. In batch experiments, parameters studied include contact time, adsorbate concentration, pH, adsorbent dose and temperature. Adsorption followed Langmuir isotherm with adsorption capacity of 10.37 and 3.28 mg/g for acid brilliant blue and procion red, respectively. Adsorption kinetic studies showed second order with respect to acid brilliant blue and first order with respect to procion red. Thermodynamic parameters such as free energy, enthalpy and entropy of adsorption were also evaluated.

Joint effects of microwave and chromium trioxide on root tip cells of Vicia faba / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The mutagenic effects of microwave and chromium trioxide (CrO(3)) on Vicia faba root tip were studied. Micronucleus assay and chromosomal aberration assay were used to determine the mitotic index, the micronucleus frequency and chromosomal aberration frequency of Vicia faba root tip cells induced by microwave and CrO(3). The results showed that the micronucleus frequency decreased, and that the mitotic index and chromosomal aberration frequency showed linear dose responses to CrO(3), in treatment of microwave for 5 s. In microwave of 25 s, the mitotic index decreased, the micronucleus frequency and chromosomal aberration frequency increased with increase of CrO(3) concentration. We concluded that microwave and CrO(3) had antagonistic effect on the mitotic index of Vicia faba root tip cells, but had synergetic effect on micronucleus frequency and chromosomal aberration frequency of Vicia faba root tip cells.

Value added eco-friendly products from tannery solid wastes.

Chrome shavings are the prominent solid wastes in tanning industry. Since chromium is known for its toxicity, the disposal of chrome shavings has been identified as a serious problem from the environmental point of view. At present, the popular utilization mode for chrome shavings is the manufacture of leather boards and related products. But this does not offer complete utilization of chrome shavings. Moreover, return per ton of chrome shavings is low if used for leather board production. In view of this, two processes have been developed to offer an alternative and better solution for the disposal of chrome shavings.The first process is preparation of parchment like membrane and the second process is related to development of leather like material. These products are analyzed for their mechanical behavior and other physicochemical properties. Parchment membrane can be used in the preparation of lampshades, chandeliers, wall hangers, table tops etc. and leather like material can be used in the preparation of chappal uppers, hand bags, purses, valets etc. The utilization of the chrome shavings in preparation of those two products not only reduces the environmental pollution but at the same time value added products can also be obtained.

Effects of dengue virus infection on peripheral blood cells of mice exposed to hexavalent chromium with drinking water.

BACKGROUND & OBJECTIVE: The occupational and non-occupational exposure to hexavalent chromium Cr (VI) is common. The effect of chromium compromises the immune response of the host. Dengue virus (DV) infection causes various changes in the peripheral blood cells. It is, therefore, possible that the chromium toxicity may affect the disease process during DV infection. The present study aims to study the effects of dengue virus infection on peripheral blood cells of mice fed Cr (VI) with drinking water. METHODS: One group of mice was given ad libitum drinking water containing Cr (VI) and the other group used as the normal control mice was given plain water to drink. At the 3, 6 and 9 wk of Cr (VI) drinking, a set of mice from each group was inoculated intracerebrally (ic) with DV and studied at the 4th and 8th day post inoculation. RESULTS: It was observed that Cr (VI) drinking led to reduction in lymphocytes, haemoglobin and the haematocrit values while the granulocyte, monocyte and platelet counts were increased. On the other hand, most of the parameters were decreased following inoculation of normal mice with DV. In Cr (VI)-fed mice the effects of DV infection were minimal. The most significant finding of these experiments was that the reduction in platelet counts following inoculation with DV was markedly less in Cr (VI)-fed mice than that in DV-inoculated normal control mice. INTERPRETATION & CONCLUSION: Cr(VI) compounds have been declared as a potent occupational carcinogen. On the contrary, Cr(III) salts such as chromium polynicotinate, chromium chloride and chromium picolinate, are used as micronutrients and nutritional supplements, and have been shown to exhibit health benefits in animals and humans. Whether therapeutic doses of chromium (III) compounds may be able to prevent the DV-induced fall in platelet counts, needs to be investigated.

Changes in selected biomarkers in freshwater teleost fish, Cyprinus carpio var. communis exposed to sublethal concentrations of chromium sulphate toxicity.

The toxicity of chromium sulphate on plasma electrolytes (Na+, K+, Cl-) level and Na+, K(+)-ATPase activity of an economically important fish, Cyprinus carpio var. communis was evaluated. During sublethal treatment, plasma sodium level was increased, whereas plasma chloride level decreased throughout the experimental period. Plasma potassium level increased upto 10th day and then declined in the rest of the study period. The Na+, K(+)-ATPase activity decreased upto 15th day of treatment and slowly recovered showing significant increase upto 25th day of treatment. The significant changes in the plasma electrolytes levels and Na+, K(+)-ATPase activity can serve as a valuable biomarker of pollutant exposure and effects.

Growth performance and nutrient utilization in black Bengal bucks (Capra hircus) supplemented with graded doses of chromium as chromium chloride hexahydrate

Black Bengal bucks (Capra hircus) were supplemented with 0, 0.2 or 0.4 mg elemental chromium (Cr) as chromium chloride hexahydrate per day for 70 days. Intake of dry matter (p0.05) effect on the plasma half life (k) and clearance rate of glucose (T1/2) during an intravenous glucose tolerance test. Area under the response curve from 0 to 180 minutes after glucose loading was lower (p<0.001) in the control group of bucks. The study revealed that Cr supplementation might promote growth and nutrient utilization in black Bengal bucks. However, little difference between the 0.2 and 0.4 mg Cr supplemented bucks suggested limited benefit of increasing the level of supplementation beyond 0.2 mg per day under the normal management regimes.

Great particles (32P) chromic phosphate for treatment of solid tumors

With the purpose studying the effectivity of an intratumoral single dose of chromic [(32)P] phosphate with great particles for the treatment of solid tumors, studies of biolimination, biodistribution and therapeutic action were carried out. Only for comparative purpose, similar studies were undertaken using a solution of sodium [(32)P] orthophosphategelatine. The results show that when sodium [(32)P] orthophosphategelatine is used, the percentage of total elimination is (85.90+8,70) per cent with a higler percentage in urine (64.50+13.70) per cent than in faeces (21.40+4.50) per cent. In biodistribution studies, the greater percentage is found in bone (15.54+2.21) per cent while only a (2.51+0.39) per cent remains in the tumor. When great particles chromic [(32)P] phosphate was intratumorally injected, we determined that the total elimination is equal (36.28+6.27) per cent, finding a higler amount in faeces (29.44+5.26) per cent than in urine (6.84+2.21) per cent. Biodistribution studies demonstrated that (49.82+5.41) per cent remains in the tumor and (9.63+4.89) per cent of the injected activity is found in the liver. On the other hand, when therapeutic action was evoluted, we observed that the percentage of tumor regression (P.T.R) is 52.0 per cent for the tumors injected with chromic [(32)P] phosphate and 0.0 per cent for those injected with sodium [(32)P] orthophosphate-gelatine. These results show that the great particles colloid of chromic [(32)P] phosphate is not safe enough for the tratment of solid tumors, since it is mobilezed from the injection point, delivering a high dose to the whole organism.

A Study of Working Environments and Workers Exposed to Chromium / 예방의학회지

For the purpose of providing the basic data for health management of workers who are exposed to chromium and for improving the quality of working environment, the authors evaluated blood and urinary level of chromium, the occupational history, AST, ALT, Hb, Hct, nasal specular examination on 287 workers who have been dealed chromium compounds in 56 manufacturing industries of five types, that is, 38 metal plating services(plating), 4 manufacture of other fabricated metal products (fabricated metal product), 5 manufacturing of dyestuff(dyestuff), 6 dressing and dyeing of leather (leather), 3 others (manufacture of pottery and ceramic household wares, motor vehicles, electronic valves and tubes and other electronic components) and also measured the level of chromium in air from February to october 1993. The results were as follows; 1. The utilized type of chromium compounds was the hexavalent state in plating, fabricated metal product, dyestuff leather and the trivalent state in other, and atmospheric chromium concentration as geometric mean was 0.0138m3(0.001~0.068 mg/m3) in plating, 0.0115 mg/m3(0.006~0.015 mg/m3) in fabricated metal product, 0.068 mg/m3 (0.002~0.019 mg/m3)in dyestuff, 0.0083 mg/m3(0.002~0.028 mg/m3) in leather, 0.0039 mg/m3(0.003~0.005 mg/m3) in other by the type of industry and it exceeded TLV-TWA (0.05 mg/m3) in five(13.6%) of plating services. 2. The geometric mean of chromium in blood was 1.54 microgram/dl(0.10~3.62 microgram/dl) in planting, 0.94 microgram/dl(0.27~2.82 microgram/dl) in fabricated metal product, 0.51 microgram/dl(0.10~3.25 microgram/dl) in dyestuff, 0.87 microgram/dl(0.15~8.00 microgram/dl) in leather 0.55 microgram/dl(0.20~2.28 microgram/dl) in other by the type of industry(P<0.001). 3. The geometric mean of chromiurn in urine was 14.47 microgram/l(6.90~28.00 microgram/l) in planting, 4.63 microgram/l(0.24~43.00 microgram/l) in fabricated metal product, 5.93 microgram/l(1.00~33.00 microgram/l) in dyestuff. 11.09 microgram/l(0.80~48.00 microgram/l) in leather, 12.41 microgram/l(10.10~41.00 microgram/l) in other by the type of industry(P<0.001). 4 As the result of nasal specular examination, twenty four cases(8.4%) of nasal septal perforation among 287 total subjects was observed, and there were 17(9.7%) cases in plating, 4 cases(14.3%) in dressing and dyeing of leather. In the comparison of chromium concentration in blood and urine between the perforated group and nonperforated group the perforated group showed a significantly higher value as 1.883+/-3.055 microgram/dl and 0.793+/-0.815 microgram/dl(P<0.001). 21.31+/-34.610 microgram/L and 9.304+/-11.079 microgram/L(P<0.001). 5. The mean concentration of chromium in blood, urine and the mean level of AST, ALT, Hb and Hct in exposure group were higher than those of control group(P<0.001).

Comparative toxicity of trivalent and hexavalent chromium compounds in fig moth Ephestia cautella (Walker).

Of the trivalent (CrSO4) and hexavalent (K2Cr2O7) chromium compounds, only the hexavalent produced significant deleterious effects on development and fertility of E. cautella, when eggs were reared on laboratory medium supplemented with different concentrations of these salts.