[Carbon monoxide contamination: an environmental health problem]. / Contaminación por monóxido de carbono: un problema de salud ambiental.

Carbon monoxide is considered to be a major factor contaminating earth's atmosphere. The main sources producing this contamination are cars using gasoline or diesel fuel and industrial processes using carbon compounds; these two are responsible for 80% of carbon monoxide being emitted to the atmosphere. This substance has a well-known toxic effect on human beings and its acute poisonous effects (including death) have been widely studied; however, its long-term chronic effects are still not known. During the last few years, experimental research on animals and studies of human epidemiology have established the relationship between chronic exposure to low and middle levels of carbon monoxide in breathable air and adverse effects on human health, especially on organs consuming large amounts of oxygen such as the heart and brain. Harmful cardiovascular and neuropsychological effects have been documented in carbon monoxide concentration in air of less than 25 ppm and in carboxyhaemoglobin levels in blood of less than 10%. The main cardiac damage described to date has been high blood pressure, cardiac arrhythm and electrocardiograph signs of ischemia. Lack of memory, attention, concentration and Parkinson-type altered movement are the neuropsychological changes most frequently associated with chronic exposure to low levels of carbon monoxide and carboxyhaemoglobin.

Contaminación por monóxido de carbono: un problema de salud ambiental / Carbon monoxide contamination: an environmental health problem

El monóxido de carbono es considerado uno de los mayores contaminantes de la atmósfera terrestre. Sus principales fuentes productoras responsables de aproximadamente 80 por ciento de las emisiones, son los vehículos automotores que utilizan como combustible gasolina o diesel y los procesos industriales que utilizan compuestos del carbono. Esta sustancia es bien conocida por su toxicidad para el ser humano. Sus efectos tóxicos agudos incluida la muerte han sido estudiados ampliamente; sin embargo, sus potenciales efectos adversos a largo plazo son poco conocidos. En los últimos años, los estudios de investigación experimentales en animales y epidemiológicos en humanos han evidenciado relación entre población expuesta en forma crónica a niveles medios y bajos de monóxido de carbono en aire respirable y la aparición de efectos adversos en la salud humana especialmente en órganos de alto consumo de oxígeno como cerebro y corazón. Se han documentado efectos nocivos cardiovasculares y neuropsicológicos en presencia de concentraciones de monóxido de carbono en aire inferiores a 25 partes por millón y a niveles de carboxihemoglobina en sangre inferiores a 10 por ciento. Las alteraciones cardiovasculares que se han descrito son hipertensión arterial, aparición de arritmias y signos electrocardiográficos de isquemia. Déficit en memoria, atención, concentración y alteraciones del movimiento tipo parkinsonismo, son los cambios neuropsicológicos con mayor frecuencia asociados a exposición crónica a bajos niveles de monóxido de carbono y carboxihemoglobina.

Carbon monoxide is considered to be a major factor contaminating earths atmosphere. The main sources producing this contamination are cars using gasoline or diesel fuel and industrial processes using carbon compounds; these two are responsible for 80 percent of carbon monoxide being emitted to the atmosphere. This substance has a well-known toxic effect on human beings and its acute poisonous effects (including death) have been widely studied; however, its long-term chronic effects are still not known. During the last few years, experimental research on animals and studies of human epidemiology have established the relationship between chronic exposure to low and middle levels of carbon monoxide in breathable air and adverse effects on human health, especially on organs consuming large amounts of oxygen such as the heart and brain. Harmful cardiovascular and neuropsychological effects have been documented in carbon monoxide concentration in air of less than 25 ppm and in carboxyhaemoglobin levels in blood of less than 10 percent. The main cardiac damage described to date has been high blood pressure, cardiac arrhythm and electrocardiograph signs of ischemia. Lack of memory, attention, concentration and Parkinson-type altered movement are the neuropsychological changes most frequently associated with chronic exposure to low levels of carbon monoxide and carboxyhaemoglobin.

Hazardous air pollutants from mobile sources in the Metropolitan Area of Mexico City.

Environmental agencies are currently in the process of implementing a new air management program, which includes the improvement of fuel quality. In this work, exhaust emissions data and estimated relative risk for various fuels testing in-use vehicles, equipped with three different exhaust emission control technologies, are presented. Aromatics, sulfur, and olefins contents; type of oxygenated compound; and Reid vapor pressure were varied. The aim also includes calculating the ozone (O3) forming potential and a relative cancer risk of emissions from current and formulated gasoline blends in Mexico. The proposed gasoline decreases carbon monoxide, total hydrocarbons (THC), and nitrogen oxides emissions by 18 and 14%, respectively, when compared with gasoline sold in the rest of the country and within ozone nonattainment metropolitan areas in Mexico, respectively.

Traffic-related occupational exposures to PM2.5, CO, and VOCs in Trujillo, Peru.

A traffic-related exposure study was conducted among 58 workers (drivers, vendors, traffic police, and gas station attendants) and 10 office workers as controls in Trujillo, Peru, in July 2002. PM2.5 was collected, carbon monoxide (CO) was measured, volatile organic compounds (VOCs) were sampled and analyzed. Newspaper vendors had the highest full-shift CO exposures (mean +/- SD: 11.4 +/- 8.9 ppm), while office workers had the lowest (2.0 +/- 1.7 ppm). Bus drivers had the highest full-shift PM2.5 exposures (161 +/- 8.9 microg/m3), while gas station attendants (64 +/- 26.5 microg/m3) and office workers (65 +/- 8.5 microg/m3) were the lowest. Full-shift benzene/toluene/ethylbenzene/xylene exposures (BTEX) among gas station attendants (111/254/43/214 microg/m3) were much higher than those among van and taxi drivers. Several of the traffic-related occupational exposures studied were elevated and are of occupational health concern.

Lead exposure and semen quality among traffic police in Arequipa, Peru.

This study examined lead exposure (n = 43) and semen quality (n = 18) among traffic police officers in Arequipa, Peru, where leaded gasoline is used. Blood lead (PbB) was measured using atomic absorption spectrophotometry, and semen was analyzed following World Health Organization (WHO) protocol. Mean PbB was 48.5 microg/dL. Although current PbB was associated with declines in several semen parameters (sperm morphology, concentration and total number of sperm), only sperm motility and viability differed significantly between the < or = 40 microg/dL and > 40 microg/dL categories, and decreased with increasing PbB in simple linear regression. Traffic police are an indicator group for excessive ambient lead exposure, and these results support earlier findings on the male reproductive toxicity of lead. The results should be interpreted cautiously since the numbers were small and the analysis was unable to control for all potential confounders due to incomplete data.

Occupational and environmental levels of mutagenic PAHs and respirable particulate matter associated with diesel exhaust in Santiago, Chile.

This work studied the mutagenic potential and polycyclic aromatic hydrocarbon (PAH) levels onto PM10 collected in diesel revision plants, in an urban area as well as in a rural area in Santiago, Chile. The PM10 average levels in diesel emission plants during working hours (there is no occupational PM10 Chilean standard) were significantly higher than the atmospheric Chilean PM10 standard and highly mutagenic and with high PAHs levels. Additionally, we evaluated the contribution of CYP1A1 and GSTM1 polymorphisms on 1-OH-pyrene urinary levels. The diesel-exposed workers carrying the CYP1A1*2A allele showed significantly higher 1-OH-P levels than the subjects from the rural area with the same genotype. The higher levels of 1-OH-P were found in individuals carrying the combined CYP1A1*2A and GSTM1 null genotype. This kind of information might be relevant to establish prevention, protection, and mitigation actions to protect public health.

Aryl hydrocarbon receptor-mediated activity of particulate organic matter from the Paso del Norte airshed along the U.S.-Mexico border.

In this study, we determined the biologic activity of dichloromethane-extracted particulate matter < 10 micro m in aerodynamic diameter (PM10) obtained from filters at three sites in the Paso del Norte airshed, which includes El Paso, Texas, USA; Juarez, Chihuahua, Mexico, and Sunland Park, New Mexico, USA. The extracts were rich in polycyclic aromatic hydrocarbons (PAHs) and had significant biologic activity, measured using two in vitro assay systems: ethoxyresorufin-(O-deethylase (EROD) induction and the aryl hydrocarbon-receptor luciferase reporter system. In most cases, both EROD (5.25 pmol/min/mg protein) and luciferase activities (994 relative light units/mg) were highest in extracts from the Advance site located in an industrial neighborhood in Juarez. These values represented 58% and 55%, respectively, of induction associated with 1 micro M ss-naphthoflavone exposures. In contrast, little activity was observed at the Northeast Clinic site in El Paso, the reference site. In most cases, luciferase and EROD activity from extracts collected from the Tillman Health Center site, situated in downtown El Paso, fell between those observed at the other two sites. Overall, a statistically significant correlation existed between PM10 and EROD and luciferase activities. Chemical analysis of extracts collected from the Advance site demonstrated that concentrations of most PAHs were higher than those reported in most other metropolitan areas in the United States. Calculations made with these data suggest a cancer risk of 5-12 cases per 100,000 people. This risk estimate, as well as comparisons with the work of other investigators, raises concern regarding the potential for adverse health effects to the residents of this airshed. Further work is needed to understand the sources, exposure, and effects of PM10 and particulate organic material in the Paso del Norte airshed.

Genotoxicity biomonitoring in regions exposed to vehicle emissions using the comet assay and the micronucleus test in native rodent Ctenomys minutus.

Exposure to motor vehicle emissions represents an important concern for possible long-term health effects. The present report describes: 1) the application and verification of the alkaline comet assay in Ctenomys minutus to detect the possible genotoxicity of automobile emissions; 2) a comparison of the comet assay results with peripheral blood micronucleus (MN) assay results performed in the same animals; and 3) the identification of agents involved in the responses and in the seasonal variation of the effects. Ctenomys minutus (Octodontidae-Rodentia) were captured in two different fields from both sides of RS/030, a highway on the coastal plain of the Brazilian state of Rio Grande do Sul. Reference animals were obtained from a nearby field that was about 3 km distant from any road. By the end of this study, 123 rodents (73 females and 50 males) were live-trapped. Our results indicate that there was an increase in cells with DNA damage for C. minutus environmentally exposed to automobile emissions, as demonstrated by the alkaline comet assay, but there was no increase in micronucleated cells. The alkaline comet assay showed age and gender differences in the response. The comet assay results suggest that adult females are the principal population affected by air pollutants from vehicle emissions. Chemical data were also collected from areas exposed to automobile exhaust and these indicated that elevated levels of hydrocarbons, metals, and NO(2) were associated with the elevated levels of damaged cells observed in the wild rodent C. minutus. Our results agree with previous data on engine and fuel components, where weak increases in damage for native rodents exposed to emissions have been observed. Other larger, controlled studies are needed to better understand how the metabolism of C. minutus affects its response to emission exposure.

Particulate suspended matters and cases of respiratory disease in Rio de Janeiro city (Brazil).

This paper investigates the existence of a possible relationship between suspended particulate matters levels and cases of respiratory diseases from a random and systematic sample of medical and air pollution records in the metropolitan area of Rio de Janeiro. Records of emergency cases of the year 1991 (months of January, June and July) were collected at Miguel Couto Hospitals and suspended particulate matter (1980-1995) at FEEMA (Rio de Janeiro Environmental Agency). The results revealed that the diseases of the respiratory system of those patients who seek the hospital's emergency care are more frequent during the wintertime. Their number increases markedly during winter months of June and July when compared with the summer's (January) number of cases. The analysis of the historical series (1980-1995) of atmospheric pollution measured at Bonsucesso monitoring station showed that the monthly figures (measured by the number of times that the value exceed the national standard, maximum daily concentration of 240 micro g (-3), are higher in wintertime (June, July and August). During this same period the level of pollution by atmospheric particulate matter in Rio de Janeiro metropolitan area measured by the annual geometric averages showed results well above the national standard (80 micro g(-3). This unfavorable situation, together with the fast growing number of new cars circulating in the city and the absence of a clear air pollution control and management plan, may contribute to an increase of the incidence and seriousness of respiratory diseases during subsequent winter months.

Niveles de contaminación por ruido en una de las principales avenidas de la ciudad de México / Noise pollution levels in a large street in Mexico city

Se reportan los resultados de la medición de los niveles de contaminación por ruido, encontrados en seis horarios a lo largo de las 24 hr del día, en una de las principales avenidad de la ciudad de México en el año de 1993. Las mediciones se efectuaron mediante un sonómetro a las: 4.00, 8.00, 11.00, 15.00, 19.00 y 23.00 hr. El nivel de ruido en el percentil 10 (NR10) en los horarios estudiados fué de 80.3, 104.8, 100.9, 103.8, 95.6 y 95.2 dB "A" a las 4.00, 8.00, 11.00, 15.00, 19.00 y 23.00 hrs. respectivamente. El nivel de ruido en el percentil 50 (NR50) en los horarios estudiados fué de 67.7, 90.5, 87.5, 90.5, 86.5, y 77.2 dB "A" respectivamente. El nivel de ruido en el percentil 90 (NR90) fué de 60.2, 85.6, 82.1, 86.8, 84.7 y 73.9 dB "A". La correlación entre el ruido y la cantidad de automóviles circulantes fué de r=0.86. estos datos muestran que los niveles de ruido en calles de denso tráfico en la ciudad de México, se mantienen por arriba de la norma considerad como saludable (70 dB), a lo largo del día asociados al tráfico automotor

Respiratory alterations due to urban air pollution: an experimental study in rats.

In order to assess the adverse effects of urban levels of air pollution, rats were used as biological indicators in a chronic exposure experiment. Animals were housed for 6 months in the center of São Paulo (the largest South American city) and were compared to controls kept for the same period in a clean area. Pollution levels were obtained from a State air pollution monitoring station, 200 m distant from the exposure place, which provided the levels of CO, SO2, particulates, and ozone. The animals were submitted to several tests focusing on the respiratory system, comprising pulmonary function tests, studies on mucociliary clearance and mucus rheology, histochemical evaluation of airways, bronchoalveolar lavage, and ultrastructural studies of the epithelium of the airways. Rats exposed to air pollution developed secretory cell hyperplasia in the airways, ultrastructural ciliary alterations, and a more rigid mucus, changes that caused mucociliary clearance impairment. In addition, nasal resistance and the number of inflammatory cells recovered by bronchoalveolar lavage were increased in air pollution exposed animals. The results obtained in the present investigation suggest that chronic exposure to urban levels of air pollution may cause respiratory lesions in rats.

Relatório de impacto no meio ambiente: o uso do metanol como combustível / Report of impact on the environment: the use of methanol as fuel

Este relatório nasceu de uma monografia destinada a fornecer subsídios à sociedade brasileira em geral a respeito das vantagens e cuidados do uso do metanol como combustível, em caráter emergencial e por tempo limitado. Seu preparo começou em meados de dezembro de 1989, quando, em carta datada de 4 de janeiro de 1990 fomos solicitados pelo Ministério das Minas e Energia a ampliá-lo e transformá-lo em estudo de impacto ambiental para atender à resoluçäo número 15/89, fruto da reuniäo de 07/12/89 do Conselho Nacional do Meio Ambiente. Neste estudo, preparado em uma semana dada à urgência da solicitaçäo, procura-se fazer uma análise global dos efeitos, positivos e negativos, resultantes da introduçäo de metanol no mercado de combustíveis do país.

Estudo de impacto no meio ambiente: o uso do metanol como combustível / Study of impact on the environmente: the use of methanol as fuel

Este documento nasceu de uma monografia destinada a fornecer subsídios à sociedade brasileira em geral a respeito das vantagens e cuidadedos do uso do metanol como combustível, em caráter emergencial e por tempo limitado. Procura-se fazer uma análise global dos efeitos, positivos e negativos, resultantes da introduçäo de metanol no mercado de combustíveis do país.