[Assessment of Hematotoxic effects of occupational exposure to unleaded petrol]

Gasoline is a complex mixture of more than 500 hydrocarbons. The elimination of lead from petrol has been associated with the addition of significant amounts of hematotoxic monocyclic aromatic hydrocarbons such as benzene, toluene and xylene [BTX]. The main purpose of this study was to ascertain whether exposure to unleaded petrol, under normal working conditions, is associated with any hematotoxic response. This was a historical cohort study in which 200 subjects with current exposure to unleaded petrol from Shiraz petrol stations as well as 200 unexposed employees were investigated. Using standard methods, atmospheric concentrations of BTX were measured. Additionally, blood samples were taken from subjects for routine biochemical tests such as RBC, WBC and platelet count, Hemoglobin, hematocrit and RDW. The geometric means of airborne concentrations of BTX were found to be 0/24, 0/37 and 0/64 ppm, respectively. The results of blood chemistry tests showed that no significant differences exist between both groups as far as biochemical tests, but RDW and hematocrit, were concerned. The average exposure of petrol station workers to BTX did not exceed the current TLVs for these chemicals. Additionally, overt hematotoxicity is unlikely to be the outcome of exposure to unleaded petrol under the conditions described in our study.

Lean diesel technology and human health: a case study in six Brazilian metropolitan regions

OBJECTIVE: Due to their toxicity, diesel emissions have been submitted to progressively more restrictive regulations in developed countries. However, in Brazil, the implementation of the Cleaner Diesel Technologies policy (Euro IV standards for vehicles produced in 2009 and low-sulfur diesel with 50 ppm of sulfur) was postponed until 2012 without a comprehensive analysis of the effect of this delay on public health parameters. We aimed to evaluate the impact of the delay in implementing the Cleaner Diesel Technologies policy on health indicators and monetary health costs in Brazil. METHODS: The primary estimator of exposure to air pollution was the concentration of ambient fine particulate matter (particles with aerodynamic diameters <2.5 μm, [PM2.5]). This parameter was measured daily in six Brazilian metropolitan areas during 2007-2008. We calculated 1) the projected reduction in the PM2.5 that would have been achieved if the Euro IV standards had been implemented in 2009 and 2) the expected reduction after implementation in 2012. The difference between these two time curves was transformed into health outcomes using previous dose-response curves. The economic valuation was performed based on the DALY (disability-adjusted life years) method. RESULTS: The delay in implementing the Cleaner Diesel Technologies policy will result in an estimated excess of 13,984 deaths up to 2040. Health expenditures are projected to be increased by nearly US$ 11.5 billion for the same period. CONCLUSIONS: The present results indicate that a significant health burden will occur because of the postponement in implementing the Cleaner Diesel Technologies policy. These results also reinforce the concept that health effects must be considered when revising fuel and emission policies.

Eosinophilic pneumonitis induced by aerosol-administered diesel oil and pyrethrum to mice / Neumonía eosinofílica inducida por aerosol de aceite diésel y piretroide en ratones

OBJECTIVE: To confirm the episode of eosinophilic pneumonitis that occurred in March 2001 in Manaus, Amazon, northern Brazil, as secondary to home aerosolization with 2 percent cypermethrin diluted in diesel compared with the more conventional 1 percent cypermethrin and soybean solution used in prophylaxis of dengue. METHODS: Four groups of Swiss mice were kept in polycarbonate cages aerosolized with one of the following solutions: diesel, diesel and cypermethrin, soy oil and cypermethrin, and saline. Three and 6 days after exposure, resistance and compliance of the respiratory system and white cell kinetics in peripheral blood and lung tissue were analyzed. RESULTS: The group exposed to diesel and cypermethrin showed higher respiratory system resistance (p < 0.001), lower compliance (p = 0.03), and increased eosinophils in blood (p = 0.03) and lung tissue (p = 0.005) compared with the other groups. There was an increase of neutrophils in the blood of all experimental groups on the third day after exposure (p < 0.001). CONCLUSIONS: We concluded that diesel associated with cypermethrin induced lung hyperresponsiveness in this experimental model and was associated with increased polymorphonuclear cells (eosinophils and neutrophils) in blood and lungs. This effect is strongest on the third day after exposure. These results are similar to the episode that occurred in Manaus in 2001 and suggest that diesel plus cypermethrin home aerosolization for arbovirosis prophylaxis should be revised.

OBJETIVO: Confirmar el episodio de neumonía eosinofílica ocurrido en marzo de 2001 en Manaus, Amazonas, en el norte de Brasil, secundario al uso de aerosol de cipermetrina diluida al 2 por ciento en aceite diésel en las viviendas en comparación con la profilaxis más convencional contra el dengue, basada en cipermetrina al 1 por ciento con aceite de soya. MÉTODOS: Se mantuvieron cuatro grupos de ratones suizos en jaulas de policarbonato y se aplicó aerosol con una de las siguientes soluciones: aceite diésel, aceite diésel y cipermetrina, aceite de soya y cipermetrina, y solución salina. Se analizaron la resistencia y el funcionamiento del sistema respiratorio y la cinética de leucocitos en sangre periférica y tejido pulmonar a los tres y seis días después de la exposición. RESULTADOS: El grupo expuesto a aceite diésel y cipermetrina mostró mayor resistencia del sistema respiratorio (P < 0,001), peor funcionamiento (P = 0,03) y más eosinófilos en sangre (P = 0,03) y tejido pulmonar (P = 0,005) que los otros grupos. Se observó un aumento de neutrófilos en sangre en todos los grupos experimentales al tercer día después de la exposición (P < 0,001). CONCLUSIONES: El aceite diésel con cipermetrina indujo una hiperrespuesta pulmonar en este modelo experimental y se asoció con un aumento en las células polimorfonucleares (eosinófilos y neutrófilos) en sangre y tejido pulmonar. Este efecto es mayor al tercer día después de la exposición. Estos efectos son similares a los observados en el episodio ocurrido en Manaus en 2001 e indican que se debe reevaluar el uso de aerosol de aceite diésel con cipermetrina para la profilaxis de arbovirus en las viviendas.

Optimum reaction time, performance and exhaust emissions of biodiesel produced by microwave irradiation

While transesterification is well established, there remain considerable inefficiencies in existing transesterification processes. In this study an alternative energy stimulant, "microwave irradiation" was used for the production of the alternative energy source, biodiesel. The optimum parametric conditions obtained from the conventional technique were applied using microwave irradiation in order to compare both systems. The results showed that application of radio frequency microwave energy offers a fast, easy route to this valuable biofuel with advantages of enhancing the reaction rate and improving the separation process. The methodology allows for the use of high free fatty acid content feedstock, including used cooking oil; hence it helps to reduce the cost of production which constitutes a major hurdle towards widespread commercialization of biodiesel. The study also showed that the optimum reaction time for microwave-enhanced biodiesel production should be highly respected. Exceeding the optimum reaction time will lead to deterioration of both biodiesel yield and purity. This paper also reported the performance and exhaust emissions from a diesel engine when fuelled with a petroleum diesel fuel and two different biodiesel fuels; one obtained by the conventional technique and the other by microwave irradiation. It was concluded that microwave-enhanced biodiesel is not, at least, inferior to that produced by the conventional technique

Micronucleus test on gas station attendants

In the present study, the micronucleus test was applied in exfoliated cells of buccal mucosa to assess the mutagenicity risk associated with occupational exposure for gas station attendants. For each individual, 2000 exfoliated buccal cells were analyzed for micronucleus frequency. A highly significant difference was found between exposed and control groups. Likewise, a significant difference was found between these groups regarding the frequency of binucleated and broken egg cells. To determine whether smoking, alcohol habit, age, gender, or working time could exert any additional effect, we determined the frequency of micronuclei and binucleated and broken egg cells amongst exposed and control individuals. The results allowed us to conclude that the individuals studied belong to a risk group and should periodically undergo biological monitoring and appropriate care.

Evaluation of the toxic effect of polycyclic aromatic hydrocarbons on semen of infertile workers in diesel and engine workshops: a prospective controlled study

The purpose of this study is to prove the toxic effect of exposure to polycyclic aromatic hydrocarbons [PAHs] on semen of infertile workers in diesel and petrol engine repair workshops. Urine and semen samples from 20 male workers exposed to hydrocarbons in diesel and petrol engines repair workshops for at least 2 years were collected. Urinary excretion of urinary 1-hydroxyrene [1-OHP], the most reliable indicator for PAHs exposure, was measured. Semen analysis and annexin -V bioassay were performed for all workers [during exposure and one year after precaution against exposure] and non-exposures [control] to document the toxic effect of PAHs exposure. PAHs exposed males showed six fold increase in 1-OHP excretions as compared to the control group. While semen volume is the same in both groups, there was significant increase in the percentage of non-aggregated sperms between the exposed and the control groups [45 +/- 26.17 and 11 +/- 7, respectively]. There was significant decrease in sperm count [Million / ml] in the exposed than the control group [44.4 +/- 37.79 and 110 +/- 55, respectively]. Asthenozospermia was found either alone or in combination with other abnormalities in 55% of the ejaculates from exposed workers, whereas, it was found alone in only 15% of the control group. Normal forms of the sperms and semen's viscosity were found significantly lower in the exposed group as compared to control group. The mean value of apoptotic sperm cells that have positive annexin-V was 42.5 +/- 14.09, while; the control group has shown no apoptotic sperm cells. Moreover, necrotic sperm cells were significantly increased in semen of exposed workers when compared to semen of control group [5.5 +/- 3.8 and 1.1 +/- 0.05, respectively]. Workers who had longer duration of exposure to PAHs had higher levels of urinary 1-OHP, percentage of annexin-V cells, lower sperm counts, lower motility, increased percentage of aggregated sperms and decreased percentage of normal sperm [r: 0.48, 0.45, -0.74, -0.79, 0.46, and 0.69, respectively]. On the other hand, after one year of precaution against exposure to PAHs all the above-mentioned parameters were spontaneously improved; level of urinary 1-OHP, ejaculate volume, nonspecific aggregate, sperm count, sperm motility, normal sperm form and sperm vitality [2.4 +/- 0.9, 3.5 +/- 1.6, 15 +/- 9.6, 56.5 +/- 30, 55 +/- 15, 60 +/- 25 and 70 +/- 23, respectively]. This study documented the deleterious toxic effect of PAHs on semen of exposed males in diesel and engine workshops that could be reversed by stoppage of exposures. However a study on a bigger number of patients is required to assess the exposure time to induce changes in semen parameters and the time needed for reversal of the toxic effect of the PAHs. Furthermore, longer follow up is recommended to evaluate the fertility of those workers

Biochemical and histopathological changes in respiratory system of rats following exposure to diesel exhaust.

Effect of exposure to diesel exhaust (DE) for different durations was evaluated using histopathological and biochemical parameters in respiratory system of the rats. Animals were exposed to 1 part DE diluted with 5 parts of clean air in a simulation chamber for 15 min/day for 1, 7, 14 and 21 days. After completion of various exposures, biochemical parameters including elastase inhibitory capacity (EIC) and protein content of the bronchial airway lavage (BAL) and histopathological changes along with lung/body weight ratio were assessed. The elastase inhibitory capacity (an index of the protection against destruction of elastin, a lung connective tissue) was maximum at 1 week indicating thereby that the body renders protection against injury by increasing EIC levels in the initial phase. However, protein content in the BALF increased after 1 week and reached maximum at 2 weeks. Histopathological changes followed similar time course of pattern with accumulation of macrophages and protein exudation. Prolonged exposure up to 3 weeks, however was accompanied by chronic inflammatory changes and thickening of alveolar septa and blood vessels. Changes in lung/body weight ratio and suspended particulate matter (SPM) deposited on filters (simulation chamber) correlated well with EIC, protein content in BALF and histopathological changes. The biochemical findings accompanied with chronic structural changes in the lungs of rats following exposure to DE could be relevant to the clinical observation of increased incidence of chronic lung diseases after continued DE exposure.

Plumbemia en madres y sus hijos recién nacidos en el Hospital Central de Maracay / Lead in mothers and newborn in the Maracay Central Hospital

Para estudiar la relación en sangre, en madres y sus recién nacidos, se determinó la plumbemia a 51 parturientas y sus hijos en el Hospital Central de Maracay. Las determinaciones de plomo se hicieron por espectrofotometría de absorción atómica de llama, encontrándose un promedio de 11,8 µg/dl en las madres y 10,5 µg/dl en los recién nacidos, no existiendo diferencias estadísticamente significativas (p<0,05) y una correlación positiva (r Pearson = o,75). Se evidenció un incremento sustancial del plomo en sangre de los niños cuyas madres trabajan fuera del hogar, y un 63 por ciento de los recién nacidos presentó plubemias superiores a 10 µg/dl, que sobrepasan los límites establecidos en países industrializados. No se encontró asociación entre plubemia y el resto de las variables estudiadas, que incluyen edad y ocupación de la madre, edad gestacional, sexo, talla y peso del recién nacido. Surge la necesidad de nuevas investigaciones para evaluar el efecto neurotóxico del plomo en el desarrollo psicomotor de niños expuestos a concentraciones superiores a 10 µg/dl, y de tomar medidas para reducir o eliminar la principal fuente de contaminación atmosférica por plomo, representada por la utilización de gasolina con derivados alquílicos de ese metal