Evidence of cytogenetic and histological damage in specimens of Astyanax lacustris (Pisces, Characidae) exposed to the hydrogen cyanide-based herbicide Dormex®

The herbicide Dormex®, a solution of hydrogen cyanamide, is a growth regulator capable of breaking the dormancy of fruit plants, and is commonly applied in agriculture. However, the biological effects of this product on non-target organisms are unknown. The present study investigated the biological response of Astyanax lacustris (Lütken, 1875) specimens exposed to Dormex® using a chromosome aberration test, the mitotic index, and the histological analysis of the gills. Forty specimens of Astyanax lacustris were obtained from a local breeding facility and divided into 10 groups (nine experimental and one control) with four fish in each aquarium (group). The control group was maintained for 24 hours in dechlorinated water while the experimental groups were allocated to one of nine different treatments, with three concentrations of Dormex®, 0.05, 0.1 and 0.5 mL L-1, and exposure for 24, 48 and 72 hours. The fish exposed to Dormex® presented chromosomal aberrations of a number of types, including chromosomal breaks, acentric fragments, decondensation, and gaps at the three Dormex® concentrations, at all exposure times. The mitotic index decreased significantly in comparison with the control group. The histological preparations of the gills revealed alterations such as hyperplasia, and lamellar fusion and edema, whereas in the control group the structure of the gills was preserved. The cytogenetic analysis revealed the genotoxic potential of the herbicide Dormex® and the morphological alterations of the gills demonstrated the sensitivity of the fish, which responded rapidly to the stressor. These findings reinforce the need for special care and restrictions on the use of these herbicides in agricultural areas located near aquatic environments.

Occupational exposure to hydrogen cyanide during large-scale cassava processing, in Alagoas State, Brazil / Exposição ocupacional ao cianeto de hidrogênio durante a produção industrial da farinha de mandioca no Estado de Alagoas, Brasil / Exposición ocupacional al cianuro de hidrógeno durante la producción industrial de la harina de mandioca en el estado de Alagoas, Brasil

Abstract: The cassava roots used for flour production contain high amounts of cyanogenic glycosides and are, therefore, potential hydrogen cyanide (HCN) releasers. This fact is the cause of an increasing health concern in the sector of cassava processing. Brazilian workers engaged in the flour production may be chronically exposed to HCN in levels above the safety limits. This hypothesis is based on the drastic reduction in cyanide content of cassava roots during a traditional Brazilian method of processing and in the physical properties of the compound, which makes it very susceptible to volatilization and air contamination. As an attempt to explore this issue, HCN exposure in Brazilian "flour houses" was evaluated in this study through environmental and biological monitoring. Four flour houses placed in Alagoas State, Brazil, were investigated. The results indicated that the cassava processors are chronically exposed to HCN at average levels between 0.464 and 3.328mg/m3 (TWA), in the work environment. This range is below the TLV-C of 5mg/m3 but not below the Action Level of 2.5mg/m3. These data may be interpreted as a possible risk to susceptible individuals. Additionally, the biological monitoring indicated a high cyanide exposure in the population study, considering urinary thiocyanate (SCN-) levels.

Resumo: As raízes da mandioca utilizadas na produção de farinha contêm altos teores de glicosídeos cianogênicos; portanto, representam fontes potenciais de liberação de cianeto de hidrogênio. Esse fato causa preocupação crescente quanto à saúde dos trabalhadores na indústria de processamento da mandioca. Os trabalhadores brasileiros na produção da farinha de mandioca podem estar cronicamente expostos ao cianeto de hidrogênio em níveis acima dos limites seguros. Essa hipótese é baseada na redução drástica do nível de cianeto nas raízes da mandioca durante o método tradicional de processamento no Brasil, e nas propriedades físicas do composto, fazendo com que seja altamente suscetível à volatilização e à contaminação atmosférica. Para explorar essa questão, o estudo avaliou a exposição ao cianeto de hidrogênio em casas de farinha brasileiras através da monitorização ambiental e biológica. Foram estudadas quatro casas de farinha localizadas no Estado de Alagoas. Os resultados mostraram que os trabalhadores no processamento da mandioca estão expostos cronicamente ao cianeto de hidrogênio em níveis médios entre 0,464 e 3,328mg/m3 (TWA). Essa faixa é abaixo do TLV-C de 5mg/m3, mas não abaixo do Nível de Ação de 2,5mg/m3. Os dados podem ser interpretados como de risco potencial para os indivíduos suscetíveis. Além disso, a monitorização biológica indicou exposição elevada ao cianeto na população do estudo, considerando os níveis urinários de tiocianato.

Resumen: Las raíces de la mandioca, utilizadas en la producción de harina contiene altas proporciones de glucósidos cianogénicos; por tanto, representan fuentes potenciales de liberación de cianuro de hidrógeno. Este hecho causa una preocupación creciente, en cuanto a la salud de los trabajadores en la industria de procesamiento de la mandioca. Los trabajadores brasileños en la producción de harina de mandioca pueden estar crónicamente expuestos al cianuro de hidrógeno a niveles superiores de los límites seguros. Esta hipótesis está basada en la reducción drástica del nivel de cianuro en las raíces de la mandioca durante el método tradicional de procesamiento en Brasil, y en las propiedades físicas del compuesto, provocando que sea altamente susceptible a la volatilización y a la contaminación atmosférica. Para explorar esta cuestión, el estudio evalúo la exposición al cianuro de hidrógeno en fábricas de harina brasileñas, a través de la monitorización ambiental y biológica. Se estudiaron cuatro fábricas de harina localizadas en el estado de Alagoas. Los resultados mostraron que los trabajadores en el procesamiento de la mandioca están expuestos crónicamente al cianuro de hidrógeno en niveles medios entre 0,464 y 3,328mg/m3 (TWA). Esta franja está por debajo del TLV-C de 5mg/m3, pero no por debajo del nivel de acción de 2,5mg/m3. Los datos pueden ser interpretados como de riesgo potencial para los individuos susceptibles. Además, la monitorización biológica indicó exposición elevada al cianuro en la población del estudio, considerando los niveles urinarios de tíocianato.

Caracterización de semillas de linaza (Linum usitatissimum L.) cultivadas en Venezuela

En los últimos años se ha promovido el consumo de linaza (Linum usitatissimum L.) como alimento funcional por sus beneficios a la salud, atribuibles principalmente a su contenido de ácidos grasos omega-3, lignanos, y fibra dietaria. En este estudio se evaluó la calidad microbiológica, composición química y las propiedades antioxidantes de la semilla de linaza cultivada en Venezuela y se comparó con una variedad canadiense de amplia venta en el país. Se determinaron coliformes totales, mohos y levaduras, S. aureus, y esporulados de los géneros Bacillus (aerobios) y Clostridium (anaerobios), humedad, grasas, proteínas, fibra dietética total, soluble e insoluble, mucílago, minerales, perfil de ácidos grasos, contenido de HCN equivalente, aw, color, polifenoles y propiedades antioxidantes como Eficiencia Antirradical (EA), concentración de antioxidante necesario para disminuir la concentración inicial en 50 % (EC50) y el tiempo necesario para alcanzar la EC50 (TEC50). Se determinaron diferencias significativas en la composición de las semillas, resaltando su elevado contenido de grasa, proteínas, ácido alfa-linolénico y fibra dietaria. Se observaron diferencias en el contenido de mucílago, pero no en el de fibra soluble, insoluble y total. La concentración de HCN equivalente en ambas semillas es del orden de 40 mg/100 g, lo cual no representa riesgos a la salud, si se consideran sus formas de consumo. La linaza venezolana contiene mayor contenido de polifenoles que la canadiense, pero la capacidad antioxidante de esta última es mayor; ambas tienen una EA calificada como media (TEC50>30 min).

Characterization of flaxseed (Linum usitatissimum L.) grown in Venezuela. In recent years, the consumption of flaxseed (Linum usitatissimum L.) has been promoted as a functional food for its health benefits, mainly attributable to its content of omega-3 fatty acids, lignans and dietary fiber. This study evaluated the microbiological quality, chemical composition and antioxidant properties of flaxseed grown in Venezuela and compared them to the values of a Canadian variety widely sold in the country. Total coliforms, molds and yeasts, S. aureus and sporulated of the genera Bacillus (aerobic) and Clostridium (anaerobic), moisture, fat, protein, total dietary fiber, soluble and insoluble, mucilage, minerals, fatty acid profile, equivalent HCN content, aw, color, polyphenols and antioxidant properties, like antiradical efficiency (AE), concentration of antioxidant needed to decrease the initial concentration by 50 % (EC50) and the time required to reach the EC50 (TEC50) were evaluated. Significant differences in seed composition were determined, where its high content of fat, protein, alfalinolenic acid and dietary fiber stand out. Differences were observed in the mucilage content, but not in soluble, insoluble and total fiber content. Equivalent HCN concentration in both seeds is in the order of 40 mg/100 g, which poses no health risks, considering their consumption patterns. Venezuelan flaxseed contains higher content of polyphenols than the Canadian does, but the antioxidant capacity of the latter is higher; both have an EA rated as average and a slow reaction time (TEC50> 30 min).

Quantificação de cianeto total nas etapas de processamento das farinhas de mandioca dos grupos seca e d'água / Total cyanide quantification in processing stages of cassava flour from dry and water groups

O objetivo deste trabalho foi quantificar a concentração de cianeto total durante as etapas de produção da farinha de mandioca dos grupos seca e d'água. Em relação à farinha seca, a concentração de cianeto total na raiz de mandioca diminuiu de 160±11,8 mg HCN/kg para 149±12,3 mg HCN/kg após a trituração, 68±2,5 mg HCN/kg após a prensagem e chegando a 5±0,2 mg HCN/kg no produto final, após o processo de torração. Na produção da farinha d'água, a raiz de mandioca apresentava teor de cianeto total de 321±21,6 mg HCN/kg e durante o processo de fermentação da raiz, o teor de cianeto total nas primeiras 24 horas de fermentação era de 297±2,7 mg HCN/kg chegando a 64±2,3 mg HCN/kg após 96 horas em repouso no tanque. Após trituração e prensagem da massa fermentada, os valores diminuíram para 50±0,6 e 36±0,4 mg HCN/kg, respectivamente, obtendo-se no produto final a concentração de 9±0,1 mg HCN/kg, sendo evidenciado a eficiência do processo de destoxificação em ambos os processamentos.

The aim of this work was to quantify the total cyanide concentration during the production stages of cassava flour from dry and water groups. In relation to dry flour, the total cyanide concentration in the cassava root reduced from 160±11.8 mg HCN/kg to 149±12.3 mg HCN/kg after grinding, 68±2.5mg HCN/kg after pressing and 5±0.2 mg HCN/kg was obtained in the final product after the roasting process. For the water flour production, the cassava root showed 321±21.6 mg HCN/kg total cyanide content, and during the fermentation process, the total cyanide content for the first 24-hour fermentation was from 297±2.7 mg HCN/kg reaching 64±2.3 mg HCN/kg after resting in a pool for 96 hours. After grinding and pressing the fermented roots, the values lowered to 50±0.6 and 36±0.4 mg HCN/kg, respectively. A concentration of 9±0.1 mg HCN/kg was obtained in the final product, evidencing the detoxification process efficiency in both processings.

Análise dos teores de ácidos cianídrico e fítico em suplemento alimentar: multimistura / Analysis of hydrogen cyanide and phytic acid contents in feeding supplements: multimixture

OBJETIVO: Este estudo objetivou quantificar o teor de ácido cianídrico em folhas de mandioca, que receberam tratamento prévio antes da secagem, e a concentração de ácido fítico na multimistura submetida à cocção úmida. MÉTODOS: Utilizou-se a multimistura produzida pela Pastoral da Criança da cidade de Pelotas (RS), constituída por: farelos de trigo (30 por cento) e arroz (30 por cento): farinhas de milho (15 por cento) e trigo (10 por cento); pós de casca de ovo (5 por cento), de folha de mandioca (5 por cento) e de sementes (5 por cento, abóbora ou girassol). Foi realizada orientação ao fornecedor da folha de mandioca sobre a forma recomendada de preparo antes da secagem. RESULTADOS: O conteúdo de ácidos cianídrico e fitatos no suplemento alimentar foram respectivamente de 85mg.kg-1 e 35.90mg.100-1. CONCLUSÃO: Verificou-se que a mudança na forma de secagem das folhas de mandioca foi eficiente para a redução de glicosídeos cianogênicos, e que o processo de torrefação dos ingredientes foi suficiente para produzir a redução de ácido fítico da multimistura aos níveis preconizados pela legislação, não sendo observadas diferenças estatisticamente significantes quando comparadas as amostras que também foram tratadas com calor úmido.

OBJECTIVE: The objective of this study was to quantify the amount of hydrogen cyanide in cassava leaves that were treated before drying and the concentration of phytic acid in a multimixture submitted to wet cooking. METHODS: The multimixture produced by the Pastoral da Criança of the city of Pelotas (RS) consisting of wheat flour (30 percent), rice flour (30 percent), corn flour (15 percent), wheat (10 percent), egg shell powder (5 percent), cassava leaves (5 percent) and pumpkin or sunflower seeds (5 percent) was used. The supplier was advised on how to process the cassava leaves before drying them. RESULTS: The hydrogen cyanide and phytic acid contents of the feeding supplement are 85mg.kg-1 and 35.90mg.100-1 respectively. CONCLUSION: Changing the way the cassava leaves were dried was efficient to reduce the amount of cyanogenic glucosides. The cooking process of the ingredients was enough to reduce the phytic acid content in the multimixture to the levels recommended by the legislation. Significant statistical differences were not observed between these samples and those treated with moist heat.

Linamarin- the toxic compound of cassava

Cassava is a widely grown root crop which accumulates two cyanogenic glucosides, linamarin and lotaustralin. Linamarin accounts for more than 80 per cent of the cassava cyanogenic glucosides. It is a beta-glucoside of acetone cyanohydrin and ethyl-methyl-ketone-cyanohydrin. Linamarin beta-linkage can only be broken under high pressure, high temperature and use of mineral acids, while its enzymatic break occurs easily. Linamarase, an endogenous cassava enzyme, can break this beta-linkage. The enzymatic reaction occurs under optimum conditions at 25ºC, at pH 5.5 to 6.0. Linamarin is present in all parts of the cassava plant, being more concentrated on the root and leaves. If the enzyme and substrate are joined, a good detoxification can occur. All the cassava plant species are known to contain cyanide. Toxicity caused by free cyanide (CN-) has already been reported, while toxicity caused by glucoside has not. The lethal dose of CN- is 1 mg/kg of live weight; hence, cassava root classification into toxic and non-toxic depending on the amount of cyanide in the root. Should the cyanide content be high enough to exceed such a dose, the root is regarded as toxic. Values from 15 to 400 ppm (mg CN- of fresh weight) of hydrocyanic acid in cassava roots have been mentioned in the literature. However, more frequent values in the interval 30 to 150 ppm have been observed. Processed cassava food consumed in Brazil is safe in regard to cyanide toxicity.

Chemical analysis of smoke of Indian cigarettes, bidis and other indigenous forms of smoking--levels of steam-volatile phenol, hydrogen cyanide and benzo(a)pyrene.

Levels of steam-volatile phenol, hydrogen cyanide and benzo(a)pyrene in various types of tobacco smoking products marketed in the country have been determined for the first time. Steam-volatile phenol levels in six popular brands of Indian cigarettes varied from 118 to 226 micrograms, and in six popular brands of bidis, from 129 to 273 micrograms. Cheroot and cigarillos yielded 400 micrograms and 333 micrograms steam-volatile phenol respectively. The hydrogen cyanide levels in the mainstream smoke of five popular brands of Indian cigarettes varied from 366 to 638 micrograms and in the mainstream smoke of four popular brands of bidis from 688 to 904 micrograms. Cheroot and cigarillos yielded 588 micrograms and 1119 micrograms hydrogen cyanide respectively. The values of benzo(a)pyrene content in Indian cigarettes varied from 85 to 114 ng and in bidis from 108 to 144 ng. Herbal bidi and cheroot had 1315 ng and 2519 ng benzo(a)pyrene respectively. Cigarettes were smoked as per international standard smoking conditions and the levels of noxious agent were found to be higher than in currently marketed western cigarettes. However, these levels in all the indigenous products including bidis cannot be directly compared with those of cigarettes as they were smoked under modified conditions.