RESUMO
One of the advantages of using biodiesel and its blends with diesel oil is the lower levels of emissions of particulate matter, sulfur dioxide, carbon monoxide, among others, making it less harmful to the environment and to humans. However, this biofuel is susceptible to microbial contamination and biodeterioration. In this sense, studies on the use of effective low toxicity biocides are being carried out, and this work aims to present the latest information (2008â»2018) available in the scientific databases, on the use of biocides in biodiesel, mainly concerning their toxicity to the environment and public health. The results showed that in relation to the control of microbial contamination, the current scenario is limited, with seven publications, in which the most studied additives were isothiazolinones, oxazolidines, thiocyanates, morpholines, oxaborinanes, thiocarbamates and phenolic antioxidants. Studies regarding direct experiments with humans have not been found, showing the need for more studies in this area, since the potential growth of biodiesel production and consumption in the world is evident. Thus, there are need for more studies on antimicrobial products for use in biodiesel, with good broad-spectrum activity (bactericidal and fungicidal), and further toxicological tests to ensure no or little impact on the environment.
Assuntos
Biocombustíveis/efeitos adversos , Desinfetantes/efeitos adversos , Monitoramento Ambiental , Saúde Pública , Monóxido de Carbono/química , Monóxido de Carbono/toxicidade , Desinfetantes/química , Gasolina , Humanos , Material Particulado/química , Material Particulado/toxicidadeRESUMO
Jatropha curcas cake, a by-product of biodiesel production, is rich in protein and has potential to be used in livestock feed; however, the presence of antinutritional factors and phorbol esters limits its use. Thus, this study investigated toxicological and reproductive effects in male Wistar rats after subchronic exposure to J. curcas cake subjected to detoxification procedures. Rats were divided into seven groups (n = 10) and treated for 60 days. The control group received commercial feed, while experimental groups received a diet containing 5% J. curcas cake nonhydrolyzed or hydrolyzed with 5 M NaOH. The cakes were unwashed or washed with ethanol or water and were autoclaved at 121°C for 30 minutes. Alkaline hydrolysis combined with ethanol washing decreased the phorbol ester concentration in the cake by 98%. Histopathological findings included diffuse degeneration of the liver and edema around the pulmonary vessels in the nonhydrolyzed groups. In addition, nontreated females mated with males of nonhydrolyzed unwashed group showed a decreased number of live fetuses and an increased placental weight. There were no signs of toxicity in rats given hydrolyzed cakes washed and unwashed, indicating that alkaline hydrolysis associated with heat treatment is an efficient method for detoxification of the J. curcas cake.
Assuntos
Ração Animal , Jatropha/química , Reprodução/efeitos dos fármacos , Sementes/química , Álcalis/química , Animais , Biocombustíveis/efeitos adversos , Dieta , Etanol/química , Temperatura Alta , Hidrólise/efeitos dos fármacos , Jatropha/efeitos adversos , Ésteres de Forbol/efeitos adversos , Ésteres de Forbol/química , Ratos , Sementes/efeitos adversosRESUMO
BACKGROUND: Previous studies have uncovered a very high prevalence of sleep disorders in general, and of sleep-disordered breathing in particular among children exposed to indoor biomass fuel pollution. However, despite the significant symptomatology, parents are unlikely to report these issues during health-care visits. OBJECTIVE: The objective of this study was to determine whether reduced caregiver perception of sleep disorders may account for the infrequent diagnosis and treatment of such problems in children residing at high altitudes and exposed to high biomass pollution. METHODS: Parents of children aged 9-15 years of three communities residing in the Pasco region in Peru located between 3800 and 4200 meters above sea level were surveyed using a validated questionnaire instrument focused on symptoms associated with sleep-disordered breathing as well as whether caregivers perceived that their child suffered from a sleep disorder. RESULTS: Among the 77 children included, 48.1% had nocturnal awakenings and 46.8% had repetitive movements and restless sleep. Habitual snoring was present in 33.8% of all children. However, only 10.4% of mothers considered that their children had sleep problems, and all of their children had positive answers for ≥4 sleep symptoms. CONCLUSIONS: Children residing at high altitudes and exposed to traditional biomass-fueled stoves exhibit an extremely high frequency of sleep symptoms that are misperceived by their mothers as being "normal." Interventions aimed at increasing parental recognition and awareness of sleep problems will be essential to foster improved diagnosis and treatment.
Assuntos
Poluição do Ar em Ambientes Fechados/efeitos adversos , Altitude , Atitude Frente a Saúde , Biocombustíveis/efeitos adversos , Cuidadores/psicologia , População Rural , Síndromes da Apneia do Sono/diagnóstico , Síndromes da Apneia do Sono/psicologia , Adolescente , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Peru , Síndromes da Apneia do Sono/epidemiologia , Inquéritos e QuestionáriosRESUMO
The aim of this investigation was to quantify organic and inorganic gas emissions from a four-cylinder diesel engine equipped with a urea selective catalytic reduction (SCR) system. Using a bench dynamometer, the emissions from the following mixtures were evaluated using a Fourier transform infrared (FTIR) spectrometer: low-sulfur diesel (LSD), ultralow-sulfur diesel (ULSD), and a blend of 20% soybean biodiesel and 80% ULSD (B20). For all studied fuels, the use of the SCR system yielded statistically significant (p < 0.05) lower NOx emissions. In the case of the LSD and ULSD fuels, the SCR system also significantly reduced emissions of compounds with high photochemical ozone creation potential, such as formaldehyde. However, for all tested fuels, the SCR system produced significantly (p < 0.05) higher emissions of N2O. In the case of LSD, the NH3 emissions were elevated, and in the case of ULSD and B20 fuels, the non-methane hydrocarbon (NMHC) and total hydrocarbon of diesel (HCD) emissions were significantly higher.
Assuntos
Poluição do Ar/prevenção & controle , Biocombustíveis/efeitos adversos , Gasolina/efeitos adversos , Emissões de Veículos/análise , Catálise , Hidrocarbonetos/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Enxofre/químicaRESUMO
Few of the numerous published studies of the emissions from biofuels-induced "indirect" land use change (ILUC) attempt to propagate and quantify uncertainty, and those that have done so have restricted their analysis to a portion of the modeling systems used. In this study, we pair a global, computable general equilibrium model with a model of greenhouse gas emissions from land-use change to quantify the parametric uncertainty in the paired modeling system's estimates of greenhouse gas emissions from ILUC induced by expanded production of three biofuels. We find that for the three fuel systems examined--US corn ethanol, Brazilian sugar cane ethanol, and US soybean biodiesel--95% of the results occurred within ±20 g CO2e MJ(-1) of the mean (coefficient of variation of 20-45%), with economic model parameters related to crop yield and the productivity of newly converted cropland (from forestry and pasture) contributing most of the variance in estimated ILUC emissions intensity. Although the experiments performed here allow us to characterize parametric uncertainty, changes to the model structure have the potential to shift the mean by tens of grams of CO2e per megajoule and further broaden distributions for ILUC emission intensities.
Assuntos
Biocombustíveis/efeitos adversos , Dióxido de Carbono/análise , Incerteza , Brasil , Carbono , Etanol , Efeito Estufa/economia , Humanos , Modelos Econômicos , Saccharum , Zea maysRESUMO
This study was realized to evaluate the production of gas and volatile fatty acids when glycerin was used to replace four forage species through the use of a semi-automated technique in vitro. The experimental design included 4 treatments and 4 replications. The treatments consisted of increasing levels of glycerin (0, 30, 50 and 70%), which was used to replace the forage plants Elephant grass, sugar cane silage, corn silage and Brachiaria grass. Replacement of the Brachiaria and Elephant grasses with glycerin linearly reduced the production of methane and carbon dioxide and ammonia nitrogen and had a positive effect on forage quality (p 0.05). With the addition of glycerin, the values for acetate concentration decreased (p 0.05); however, when added glycerin there was increased in propionic and butyric acid concentration (p 0.05). Substitution of forage species for glycerin by tests for semi-automatic technique in vitro reduce the production of greenhouse gases (CH4 and CO2) which reduction in energy loss, and increase volatile fatty acids propionic and butyric.(AU)
Este estudo foi realizado para avaliar a produção de gás e ácidos graxos voláteis da glicerina em substituição à quatro espécies forrageiras pela técnica semi-automática in vitro. O delineamento experimental incluiu 4 tratamentos e 4 repetições. Os tratamentos consistiram em níveis crescentes de glicerina (0, 30, 50 e 70%), em substituição às forrageiras capim Elefante, cana-de-açúcar, silagem de milho e Braquiária. A substituição das gramíneas forrageiras capim Brachiaria e capim Elefante pela glicerina afetou a produção de metano, dióxido de carbono e nitrogênio amoniacal e teve um efeito positivo sobre a qualidade da forragem (p 0,05). Com a adição de glicerina, os valores da concentração de acetato reduziram (p 0,05). Todavia, a adição de glicerina aumentou as concentrações de ácido propiônico e butírico (p 0,05). A substituição de espécies forrageira pela glicerina através da técnica semiautomática in vitro reduz a produção de gases de efeito estufa (CH4 e CO2) que diminuirá a perda de energia e eleva os ácidos graxos voláteis propiônico e butírico.(AU)
Assuntos
Biocombustíveis/efeitos adversos , Biocombustíveis/análise , Biocombustíveis/provisão & distribuição , Glicerol/administração & dosagem , Glicerol/efeitos adversos , Biodegradação Ambiental , Butiratos , AcetatosRESUMO
This study was realized to evaluate the production of gas and volatile fatty acids when glycerin was used to replace four forage species through the use of a semi-automated technique in vitro. The experimental design included 4 treatments and 4 replications. The treatments consisted of increasing levels of glycerin (0, 30, 50 and 70%), which was used to replace the forage plants Elephant grass, sugar cane silage, corn silage and Brachiaria grass. Replacement of the Brachiaria and Elephant grasses with glycerin linearly reduced the production of methane and carbon dioxide and ammonia nitrogen and had a positive effect on forage quality (p 0.05). With the addition of glycerin, the values for acetate concentration decreased (p 0.05); however, when added glycerin there was increased in propionic and butyric acid concentration (p 0.05). Substitution of forage species for glycerin by tests for semi-automatic technique in vitro reduce the production of greenhouse gases (CH4 and CO2) which reduction in energy loss, and increase volatile fatty acids propionic and butyric.
Este estudo foi realizado para avaliar a produção de gás e ácidos graxos voláteis da glicerina em substituição à quatro espécies forrageiras pela técnica semi-automática in vitro. O delineamento experimental incluiu 4 tratamentos e 4 repetições. Os tratamentos consistiram em níveis crescentes de glicerina (0, 30, 50 e 70%), em substituição às forrageiras capim Elefante, cana-de-açúcar, silagem de milho e Braquiária. A substituição das gramíneas forrageiras capim Brachiaria e capim Elefante pela glicerina afetou a produção de metano, dióxido de carbono e nitrogênio amoniacal e teve um efeito positivo sobre a qualidade da forragem (p 0,05). Com a adição de glicerina, os valores da concentração de acetato reduziram (p 0,05). Todavia, a adição de glicerina aumentou as concentrações de ácido propiônico e butírico (p 0,05). A substituição de espécies forrageira pela glicerina através da técnica semiautomática in vitro reduz a produção de gases de efeito estufa (CH4 e CO2) que diminuirá a perda de energia e eleva os ácidos graxos voláteis propiônico e butírico.
Assuntos
Biocombustíveis/análise , Biocombustíveis/efeitos adversos , Biocombustíveis/provisão & distribuição , Biodegradação Ambiental , Glicerol/administração & dosagem , Glicerol/efeitos adversos , Acetatos , ButiratosRESUMO
OBJECTIVES: The aim of this study was to assess the differences associated to the change of biofuel used to cook as a way to estimate the proportion of respiratory abnormalities of respiratory function associated to biomass exposure. METHODS: A cross-sectional study was designed to evaluate the respiratory function through spirometry in subjects cooking with biomass or natural gas. All patients were evaluated by a general physician and a pulmonologist. We compared the prevalence of spirometry abnormalities across those cooking with natural gas versus those cooking with biofuel. A multivariable logistic regression and multiple linear regression were used to adjust differences by potential confounding factors. RESULTS: 203 subjects were studied. There was a significant increase in the prevalence of severe obstructive pattern (OR 5.50; 95 % CI 1.17-25.79) in subjects who cook with biomass compared with natural gas users. Values of forced expired volume in one second (FEV1) and forced vital capacity (FVC) were statistically lower among those cooking with biomass. The prevalence of respiratory morbidity and symptoms were not statistically significant between both groups. CONCLUSIONS: These findings suggest that replacing biomass fuel by natural gas may be an important public health intervention in Colombia, because it can reduce the prevalence of abnormal patterns of pulmonary function.
Assuntos
Biocombustíveis/efeitos adversos , Biomassa , Culinária , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Fumaça/efeitos adversos , Adulto , Idoso , Colômbia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Saúde da População Rural , EspirometriaRESUMO
BACKGROUND: Multiple studies have evaluated the prevalence of sleep apnea in pediatric populations. Although environmental exposures to cigarette smoke (ECS) increase the risk of habitual snoring, no studies have thus far examined the potential contribution of indoor pollution in children. OBJECTIVE: To determine the frequency of symptoms associated with sleep apnea in children exposed to traditional wood-burning stoves to open fire, and assess whether symptoms subside following implementation of improved less environmentally contaminating stoves. METHODS AND MATERIALS: Residents of the communities of Chucllapampa, Sayhuapata, and Alparcuna in Cangallo province, department of Ayacucho, Peru were surveyed on two occasions within 12 months before and after the installation of an improved Inkawasi wood stove. The frequency of symptoms associated with sleep apnea was assessed in all children <15 years of age using a previously validated questionnaire. RESULTS: Parents of 59 children (62.7% males; mean age 7.76 ± 4.2 years) were interviewed representing >97% of the children in those small villages. The most common symptoms included nighttime awakenings, habitual snoring, repetitive movements during sleep, nasal congestion, and sore throat. After implementation of improved stoves in the homes, snoring (52.5% vs. 18.2%, P < 0.0001) nasal congestion (33.9% vs. 1.8%, P < 0.0001), behavioral hyperactivity (28.8% vs. 3.8%, P < 0.002), nighttime awakenings (42.4% vs. 1.7%, P < 0.0001), sore throat (38.2% vs. 5.5% P < 0.0001), breathing through the mouth during the day (33.9% vs. 1.8%, P < 0.001), daytime sleepiness (21.1% vs. 1.8%, P < 0.003), and falling asleep at school (14.6% vs. 0%, P < 0.03) were all significantly improved. CONCLUSIONS: Children exposed to traditional biomass fuel stoves had a higher frequency of symptoms related to sleep apnea, which decrease with improvements in biomass pollution.
Assuntos
Poluição do Ar em Ambientes Fechados/efeitos adversos , Biocombustíveis/efeitos adversos , Biomassa , Exposição Ambiental/efeitos adversos , Síndromes da Apneia do Sono/etiologia , Ronco/etiologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Peru , Prevalência , Síndromes da Apneia do Sono/epidemiologia , Ronco/epidemiologia , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Exposure to fine fractions of particulate matter (PM(2.5)) is associated with increased hospital admissions and mortality for respiratory and cardiovascular disease in children and the elderly. This study aims to estimate the toxicological risk of PM(2.5) from biomass burning in children and adolescents between the age of 6 and 14 in Tangará da Serra, a municipality of Subequatorial Brazilian Amazon. METHODS: Risk assessment methodology was applied to estimate the risk quotient in two scenarios of exposure according to local seasonality. The potential dose of PM(2.5) was estimated using the Monte Carlo simulation, stratifying the population by age, gender, asthma and Body Mass Index (BMI). RESULTS: Male asthmatic children under the age of 8 at normal body rate had the highest risk quotient among the subgroups. The general potential average dose of PM(2.5) was 1.95 µg/kg.day (95% CI: 1.62 - 2.27) during the dry scenario and 0.32 µg/kg.day (95% CI: 0.29 - 0.34) in the rainy scenario. During the dry season, children and adolescents showed a toxicological risk to PM(2.5) of 2.07 µg/kg.day (95% CI: 1.85 - 2 .30). CONCLUSIONS: Children and adolescents living in the Subequatorial Brazilian Amazon region were exposed to high levels of PM(2.5) resulting in toxicological risk for this multi-pollutant. The toxicological risk quotients of children in this region were comparable or higher to children living in metropolitan regions with PM(2.5) air pollution above the recommended limits to human health.