Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MEXICO”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed2000

Child and adolescent suicide deaths in New Mexico, 1990-1994.

The suicide death rate in New Mexico is consistently higher than the national rate. Among adolescents, suicide is the third leading cause of death nationally, but in New Mexico it is the second leading cause of death. This study describes the pattern of adolescent suicide deaths in New Mexico. We conducted a retrospective review of all medical examiner autopsies for adolescent suicides (ages 20 years and younger) in New Mexico from 1990-1994. Records were reviewed for demographics and possible contributing factors such as depression, previous attempts, and alcohol and drug use. We identified 184 suicide deaths among children and adolescents ages 9-20 years for an overall rate of 12.9 per 100,000. Our rates for ages 5-9 years (0.2), 10-14 years (3.8), and 15-19 years (22.3) are over twice the U. S. rates. Suicide deaths resulted primarily from firearms (67%), hanging (16%), poisoning (6%), inhalation (4%), and other methods (7%). Method varied by ethnicity (p = .01) and gender (p = .03); males and non-Hispanic Whites were overrepresented among firearm deaths. Firearm ownership was known in 60 (48%) of the firearm deaths. Of these, 53% of the firearms belonged to a family member, 25% to the decedent, and 22% to a friend. Over one-third of decedents (41%) experienced mental disorders, primarily depressed mood and clinical depression. Previous suicide attempts were noted for 15% of the decedents. Some 50% of the decedents had alcohol or drugs present at the time of death; among American Indians/Alaska Natives, 74% had drugs or alcohol present (p = .003). Targeted interventions are needed to reduce adolescent suicide in New Mexico. We suggest raising awareness about acute and chronic contributing factors to suicide; training physicians to look for behavioral manifestations of depression; and involving physicians, teachers, and youth activity leaders in efforts to limit firearm accessibility, such as advising parents to remove firearms from their households.

Adolescent↗
PubMed2003

Fluoride intake from foods, beverages and dentifrice by children in Mexico.

OBJECTIVES: This investigation monitored fluoride ingestion in Mexican children who were susceptible to developing dental fluorosis. METHODS: Total fluoride intake, from dietary and toothpaste samples, was determined in 15-36-month-old children from Mexico City and Veracruz, Mexico. A duplicate plate technique was used. Plasma fluoride levels were also determined in this group of children. RESULTS: The children ingested a mean (+/-SD) of 0.20 +/- 0.08 and 0.18 +/- 0.07 mg fluoride/kg/day, in Mexico City and Veracruz, respectively. There was no statistically significant difference between the fluoride ingested by children in the two cities (P > 0.9). Plasma from children in Mexico City and Veracruz contained a mean of 1.30 +/- 0.81 and 0.87 +/- 0.72 micro mol fluoride/l, respectively, and these values were not significantly different. CONCLUSIONS: Our results lead to the conclusion that mean fluoride ingested from the combination of foods and beverages was within the proposed safe threshold for fluoride intake of 0.05-0.07 mg F/kg/day. Most of the fluoride intake by these children was derived from the ingestion of fluoridated toothpaste. When all sources of ingested fluoride were added and total fluoride intake was calculated, the children, both in Mexico City and Veracruz, were ingesting amounts of fluoride well above the upper limits of the proposed safe threshold for fluoride intake.

Beverages↗
PubMedDate not supplied

A study of the conversion from paid to altruistic blood donors in New Mexico.

We investigated the recent conversion of the New Mexico blood supply from a donor recruitment base which depended almost entirely upon paid, responsibility fee, and insured donors to 100 per cent reliance upon altruistic donors. Blood Services of New Mexico (BSNM) effected this change. The local Red Cross played a key role in interpreting the change to the community and in providing entree for BSNM recruiters to the right places in the community, resulting in the enlistment of an almost entirely new group of donors who had never been asked to give blood before. The sequence of decision making is identified in relation to the detailed results during the transition. Altruistically donated blood did not significantly alter the incidence of HBsAg in the New Mexico blood supply. The supply of blood was not interrupted or diminished, the range and quality of blood services improved and the cost of blood service to the patient was reduced. The New Mexico community responded magnificently, although focal responsibility for the success of this project rests with a small number of key individuals. New Mexico now has an altruistically donated blood supply.

Blood Donors↗
PubMedDate not supplied

Lead-glazed ceramic ware and blood lead levels of children in the city of Oaxaca, Mexico.

Although Mexico substantially reduced use of leaded gasoline during the 1990s, lead-glazed pottery remains a significant source of population exposure. Most previous studies of lead in nonoccupationally exposed groups in Mexico have been conducted in the Mexico City metropolitan area. Oaxaca, a poor southern state of Mexico, has a centuries-old tradition of use of low temperature lead-glazed ceramic ware manufactured mainly by small family businesses. We measured blood lead levels in 220 8-10-y-old children (i.e., not from pottery-making families) who were students in the innercity of Oaxaca and in the mothers of all children. The geometric mean blood lead level of the children was 10.5 microg/dl (+7.0/-4.3 microg/dl standard deviation; range = 1.3-35.5 microg/dl). The corresponding mean value for the mothers was 13.4 (+9.0/-5.4 microg/dl standard deviation; range = 2.8-45.3 microg/dl). We used cutoffs that were greater than or equal to 10 microg/dl, 20 microg/dl, and 30 microg/dl, and we determined that 54.9%, 10.3%, and 3.0% of the children were at or above the respective criteria. We accounted for 25.2% of the variance in blood lead levels of the children, using maternal responses to a questionnaire that assessed possible lead sources in a linear multiple-regression model. The most important factors related to lead levels were family use of lead-glazed pottery, use of animal fat in cooking, and family income. The addition of maternal blood lead level to the model increased accounted variance in blood lead to 48.0%. In logistic-regression modeling of children's blood lead levels, we used a cutoff of greater than or equal to 10 microg/dl, and we found that use of lead-glazed pottery was the most important of all questionnaire items that were predictive of blood lead levels (odds ratio = 2.98). In Oaxaca, as is the case elsewhere in Mexico, lead-glazed ceramic ware remains a significant risk factor for elevated blood lead levels in children.

Ceramics↗
PubMed1998

Health-related quality of life for rural American Indians in New Mexico.

OBJECTIVES: To determine health-related quality of life for rural American Indians using an economical telephone surveillance system. DESIGN: We interviewed 618 American Indians by telephone about health-related quality of life using an adaptation of the Behavioral Risk Factor Surveillance System questionnaire. RESULTS: A smaller proportion of rural New Mexico American Indians (50.7%) reported their general health as 'excellent' or 'very good' compared to the overall New Mexico (58.2%) and US populations (57.9%). American Indians reported a mental health limitation more frequently than the New Mexico and the US populations. However, 13% fewer rural New Mexico American Indians reported a limitation in usual activities. Most limitations were due to musculoskeletal conditions or diabetes mellitus. Survey respondents were found to be representative of the rural American Indian population as reported by the 1990 US Census Bureau by tribal group affiliation and age, but were not representative by income, education, and gender. CONCLUSIONS: Health-related quality of life for rural American Indians differs little from that of other New Mexicans and the general US population; however, when physical and mental health was rated as poor, fewer American Indians reported a limitation in usual activities. A telephone survey focusing on New Mexico American Indians is an efficient method by which to conduct surveillance of health-related quality of life.

Adolescent↗
PubMed2005

Effect of air pollution on olfactory function in residents of Mexico City.

To our knowledge there has been no study of the effect of everyday air pollution on olfactory function. It was therefore the aim of this study to compare the olfactory performance of long-term residents of Mexico City, an environment with high air pollution, with the olfactory performance of residents of the Mexican state of Tlaxcala, a region geographically similar to Mexico City but with low air pollution. Healthy volunteers [82 Mexico City subjects (MEX), 86 Tlaxcala subjects (TLX)] 20-63 years of age and balanced for age and gender between the two localities were tested for the perception of the odors of everyday beverages presented in squeeze bottles. When tested with ascending concentrations of stimuli in a three-way oddball paradigm, residents of Tlaxcala detected the odors of instant coffee and of an orange drink at significantly lower concentrations than residents of Mexico City. They also performed significantly better in discriminating between the two similar-smelling Mexican beverages horchata and atole in an oddball test. Significant differences between the two populations in overall olfactory performance were apparent in three of the four age classes (20- to 29-, 30- to 39-, and 40- to 49-year-old subjects) but not in the 50-63 years age class. About 10% of MEX subjects compared to about 2% of TLX subjects were judged to have poor olfactory function; all were from the older age classes (mean age: 48.6 years). Thus, air pollution in Mexico City appears to have a substantial impact on olfactory function even in young and middle-aged residents.

Adult↗
PubMed1979

Altitude and ischemic heart disease in tricultural New Mexico: an example of confounding.

The relationship of male white ischemic heart disease (IHD) death rates to altitude falls to negligible levels when New Mexico populations are separated into Hispanic and Anglo. Low rates of IHD mortality characterize Hispanic males in New Mexico regardless of altitude. In comparison, New Mexico Anglo males have rates near the US average. The variable showing the most consistent positive relationship with altitude is per cent Hispanic. Mortimer et al. (N Engl J Med 296:581--587, 1977) reported a reduction in coronary heart disease mortality in New Mexico white males with an increase in altitude. The current authors claim that this is an example of confounding. They find that the relationship between IHD mortality and altitude is largely due to the intervening variable, per cent Hispanic. Ethnicity demands major attention in epidemiologic studies in tricultural New Mexico.

Altitude↗
PubMed1995

Effects of urban air pollutants on emergency visits for childhood asthma in Mexico City.

The metropolitan area of Mexico City, Mexico, has serious air pollution problems. Although air contaminants may contribute to clinical asthma, there are at present no data on the relation between air pollution exposure and childhood asthma in Mexico City. The authors reviewed data on emergency visits from January to June 1990 at one major pediatric hospital in Mexico City. They used a Poisson regression model to study the relation between the number of daily emergency visits for asthma and air pollutant levels. The levels of ozone and sulfur dioxide-exposure were significantly associated with the number of emergency visits for asthma. After adjustment for potential confounding factors, the multivariate regression model predicted that an increase of 50 ppb in the 1-hour maximum ozone level would lead to a 43% increase in the number of emergency visits for asthma on the following day. Exposure to high ozone levels (> 110 ppb) for 2 consecutive days increased the number of asthma-related emergency visits by 68 percent. The results of this study suggest that ozone exposure is positively associated with the number of children's emergency visits for asthma in Mexico City.

Adolescent↗
PubMed1974

Rural health care in Mexico?

A very large percentage of Mexico's population living in rural areas lacks resources for health care. Any new effort to provide such care must emphasize the health of the infant population because of the high percentage of infants in the country. Plans made at the national level have not been correlated with the conditions that exist in rural areas. For example, the majority of university programs are oriented toward urban medical practice, and the construction of more schools of medicine to solve the problem of doctors in rural areas is based on a mistaken premise. This problem has not been solved even in developed countries such as the United States where, as in Mexico, graduates in medicine migrate to the cities where optimal conditions are met for practicing the type of medicine for which they have been trained. Furthermore, it is both expensive and illogical to maintain urban doctors in rural areas where they cannot practice their profession for lack of resources; to do so is to deny the purpose of their education (27). Conventional schools of medicine, for reasons of investment and of structure, should teach only very selected groups of students who, on finishing their training, are fully capacitated to practice specialized medicine. A different system is required if we are to provide adequate health care in the rural communities. A system such as that described herein, adapted to the real need of rural communities, would avoid the necessity to create dysfunctional bureaucracies and would not destroy those institutions which have proved useful in the past. This study should be considered as one of the many pilot programs that should be initiated in order to determine the type of program that would best solve the problem of health care in rural Mexico. Other programs already being considered at the National Autonomous University of Mexico include the A36 plan of the Faculty of Medicine, now in operation; the work of C. Biro carried out in Netzahualcoyotl City (both focused on providing medical care to the urban poor); and the Open University program. Unless an efficient program designed to meet the needs of rural communities is quickly put into operation, Mexico will, in the near future, be facing the same problems now confronting Southeast Asia.

Community Medicine↗
PubMed2005

Prevalence of antibodies to onchocerca volvulus in residents of Oaxaca, Mexico, treated for 10 years with ivermectin.

Studies to determine the prevalence of antibodies to Onchocerca volvulus, prior to and after actions carried out to interrupt transmission, are scarce in Mexico. Here we report the prevalence of immunoglobulin G (IgG) and IgG4 antibodies in an enzyme-linked immunosorbent assay (ELISA) against a crude extract of O. volvulus adult worm in serum samples from persons under noninterrupted biannual treatment with ivermectin in areas of onchocercosis endemicity in Mexico. To perform the prevalence studies, the ELISA procedures were first evaluated. Serological studies were performed with serum samples from skin microfilaria carriers from Guatemala and from people microfilariodermic negative living in the same area as the Guatemalan patients. Sensitivity values for IgG or IgG4 detection were 71 and 86%, while specificities were 92 and 100%, respectively. No anti-O. volvulus antibodies were found in samples from nonendemic controls from Mexico, but 3 of 71 samples from residents in the onchocercosis area of Oaxaca, Mexico, and who have been under ivermectin treatment during the last 10 years were only positive to IgG. Notwithstanding that the IgG4 isotype was not detected and a low (4.2%) anti-O. volvulus IgG antibody prevalence was found, a seroepidemiological follow-up must be performed in order to confirm interruption of onchocercosis transmission in the area of Oaxaca, Mexico, in which onchocercosis is endemic.

Adolescent↗
PubMed1997

Decreased capacity for type-specific-antigen synthesis accounts for high prevalence of nontypeable strains of group B streptococci in Mexico.

The low incidence of group B streptococcal (GBS) invasive neonatal disease in Mexico has been attributed to the low prevalence of serotype III strains, a major serotype in developed countries. In addition, nontypeable strains account for 12% of the isolates in Mexico and < 1% of the isolates in the United States. In this study, 57 GBS isolates (28 nontypeable by the Lancefield procedure) from carrier and infected neonates and women from Mexico were also examined for the presence of type-specific antigen by an enzymatic procedure using N-acetylmuramidase digestion of the cell wall to release soluble type-specific antigen. Of the 28 nontypeable strains from Mexico, 23 were typeable by the enzyme extraction procedure, with serotype III being the predominant serotype in invasive disease. These results suggest that nontypeable isolates of GBS should be further examined by the enzymatic extraction procedure to determine the presence of type-specific antigen. Furthermore, these limited results suggest that serotype III is likely a major serotype in invasive disease also in Mexico.

Antigens, Bacterial↗
PubMed2004

Rapid detection of rifampin resistance in Mycobacterium tuberculosis isolates from India and Mexico by a molecular beacon assay.

We assessed the performance of a rapid, single-well, real-time PCR assay for the detection of rifampin-resistant Mycobacterium tuberculosis by using clinical isolates from north India and Mexico, regions with a high incidence of tuberculosis. The assay uses five differently colored molecular beacons to determine if a short region of the M. tuberculosis rpoB gene contains mutations that predict rifampin resistance in most isolates. Until now, the assay had not been sufficiently tested on samples from countries with a high incidence of tuberculosis. In the present study, the assay detected mutations in 16 out of 16 rifampin-resistant isolates from north India (100%) and in 55 of 64 rifampin-resistant isolates from Mexico (86%) compared to results with standard susceptibility testing. The assay did not detect mutations (a finding predictive of rifampin susceptibility) in 37 out of 37 rifampin-susceptible isolates from India (100%) and 125 out of 126 rifampin-susceptible isolates from Mexico (99%). DNA sequencing revealed that none of the nine rifampin-resistant isolates from Mexico, which were misidentified as rifampin susceptible by the molecular beacon assay, contained a mutation in the region targeted by the molecular beacons. The one rifampin-susceptible isolate from Mexico that appeared to be rifampin resistant by the molecular beacon assay contained an S531W mutation, which is usually associated with rifampin resistance. Of the rifampin-resistant isolates that were correctly identified in the molecular beacon assay, one contained a novel L530A mutation and another contained a novel deletion between codons 511 and 514. Overall, the molecular beacon assay appears to have sufficient sensitivity (89%) and specificity (99%) for use in countries with a high prevalence of tuberculosis.

Antibiotics, Antitubercular↗
PubMed2006

Molecular diversity of rabies viruses associated with bats in Mexico and other countries of the Americas.

Bat rabies and its transmission to humans and other species in Mexico were investigated. Eighty-nine samples obtained from rabid livestock, cats, dogs, and humans in Mexico were studied by antigenic typing and partial sequence analysis. Samples were further compared with enzootic rabies associated with different species of bats in the Americas. Patterns of nucleotide variation allowed the definition of at least 20 monophyletic clusters associated with 9 or more different bat species. Several lineages associated with distinctive antigenic patterns were found in rabies viruses related to rabies in vampire bats in Mexico. Vampire bat rabies virus lineages associated with antigenic variant 3 are widely spread from Mexico to South America, suggesting these lineages as the most likely ancestors of vampire bat rabies and the ones that have been moved by vampire bat populations throughout the Americas. Rabies viruses related to Lasiurus cinereus, Histiotus montanus, and some other not yet identified species of the genus Lasiurus were found circulating in Mexico. Long-range dissemination patterns of rabies are not necessarily associated with migratory bat species, as in the case of rabies in Desmodus rotundus and Histiotus montanus. Human rabies was associated with vampire bat transmission in most cases, and in one case, rabies transmission from free-tailed bats was inferred. The occurrence of rabies spillover from bats to domestic animals was also demonstrated. Genetic typing of rabies viruses allowed us to distinguish trends of disease dissemination and to address, in a preliminary fashion, aspects of the complex evolution of rabies viruses in different host-reservoir species.

Amino Acid Sequence↗
PubMed2006

Differences in cancer incidence among Indians in Alaska and New Mexico and U.S. Whites, 1993-2002.

Cancer incidence for American Indians and Alaska Natives is typically reported as a single rate for all U.S. indigenous populations combined. Previously reported combined rates suggest that American Indians and Alaska Natives have lower cancer incidence rates compared with the U.S. population. Alaska Native people comprise three major ethnic groups: Eskimo, Indian, and Aleut people. We examined cancer incidence from only Alaska Indians and compared incidence rates with an American Indian population living in New Mexico. These data indicate striking differences in cancer patterns between two American Indian populations. Cancer data for the years 1993 to 2002 for American Indians of New Mexico and U.S. Whites are from the National Cancer Institute Surveillance, Epidemiology, and End Results Program Public-use data set. Data for Alaska Indians are from the Alaska Native Tumor Registry, which is also a Surveillance Epidemiology and End Results Program participant. Overall, cancer incidence rates for all sites combined in New Mexico Indian men and women were lower than U.S. White rates, whereas Alaska Indian men and women exceeded U.S. rates. In comparing Alaska and New Mexico Indians, we observed a 2.5-fold higher incidence of cancer among Alaska Indians. The largest differences between the two Indian populations were noted primarily in cancers associated with tobacco use, including cancers of the oral cavity/pharynx, esophagus (only in men), colon and rectum, pancreas, larynx (men), lung, prostate, and urinary bladder (men). Lung cancer rates in Alaska Indian men and women were 7 and 10 times those of New Mexico Indian men and women.

Alaska↗
PubMed1996

Is DDT use a public health problem in Mexico?

We review the potential impact of DDT on public health in Mexico. DDT production and consumption patterns in Mexico during the last 20 years are described and compared with those in the United States. In spite of the restrictions on DDT use in antimalaria campaigns in Mexico, use of DDT is still higher than in other Latin American countries. We analyzed information from published studies to determine accumulated levels of this insecticide in blood, adipose tissue, and breast milk samples from Mexican women. Current lipid-adjusted DDE levels from women living in Mexico City are 6.66 ppb in mammary adipose tissue and 0.594 ppm in total breast milk. Finally, the methodological limitations of existing epidemiological studies on DDT exposure and breast cancer are discussed. We conclude that DDT use in Mexico is a public health problem, and suggest two solutions: identification of alternatives for the control of malaria and educational intervention to reduce DDT exposure. We also recommend strengthening epidemiological studies to evaluate the association between accumulated DDT levels in adipose tissue and breast cancer incidence among Mexican women.

Adipose Tissue↗
PubMedDate not supplied

AIDS mortality trends in Mexico, 1988-1997.

OBJECTIVE: To assess the geographic distribution and trends of AIDS deaths for the 1988-1997 period in Mexico. MATERIAL AND METHODS: Crude and adjusted mortality rates were estimated for the 1988-1997 period. A trend test was performed using the simple linear regression method. Standardized mortality ratios (SMR) and years of potential life lost (YPLL) were calculated for each Mexican state. RESULTS: During the study period (1988-1997), there were 26,999 AIDS deaths in Mexico; 86.5% (23,354) of them were among men. The mean age at the time of death was 38.4 years for men and 37.7 years for women (p > 0.05). The crude AIDS mortality rate for the period of study was 3.02 cases (95% CI: 2.94, 3.06) per 100,000 inhabitants. The adjusted rate was 3.13 (95% CI: 3.09, 3.17), with 5.22 (95% CI: 5.16-5.29) for men and 0.82 (95% CI: 0.79-0.84) for women. The states with the highest SMR were: Baja California (SMR: 248.69; 95% CI: 234.02-263.36), Mexico City (SMR: 220.74; 95% CI: 215.57-225.91), and Jalisco (SMR: 169.16; 95% CI: 162.88-175.44). Similarly, a Potential Lost Life Years Index (PLLYI) analysis by state showed a greater risk of premature AIDS mortality in the same states [Baja California (PLLYI index: 236.33; 95% CI: 233.97-238.68), Mexico City (PLLYI: 194.68; 95% CI: 193.88-195.48), and Jalisco (PLLYI: 170.69; 95% CI: 169.60-171.79)]. CONCLUSIONS: Mortality trends indicate that AIDS mortality in Mexico increased by an annual rate of 23% between 1988 and 1997. The adjusted AIDS mortality rate increased from 0.75 per 100,000 in 1988, to 4.20 per 100,000 in 1997, with the largest burden of mortality in men (male to female ratio of 6:1). We therefore expect that a decreasing effect on AIDS mortality trends will be observed in the next years. The English version of this paper is available too at: http://www.insp.mx/salud/index.html.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Seroprevalence of hepatitis B in pregnant women in Mexico.

OBJECTIVE: To determine the seroprevalence of hepatitis B in pregnant women from several regions of Mexico, as well as the risk factors associated with its occurrence. MATERIAL AND METHODS: A cross-sectional study was conducted between May and August 2000. It included 9,992 pregnant women attending the health services of the Mexican Institute of Social Security (Instituto Mexicano del Seguro Social-IMSS) in five cities: Tijuana, Ciudad Juarez, Acapulco, Cancun, and Mexico City (northeast and southeast regions). RESULTS: The overall prevalence for confirmed cases was 1.65% (165/9,992). The prevalences for individual cities were as follows: Tijuana, 1.27%; Ciudad Juarez, 1.46%; Acapulco, 2.47%; Cancun, 0.93%; northeastern Mexico City, 1.20%, and southeastern Mexico City, 2.52%. The risk factors found to be associated with HBsAg were: age, age at first sexual intercourse, city (Acapulco and southeastern Mexico City), and marital status (single or divorced). CONCLUSIONS: The prevalence of HBsAg in pregnant women (1.65%) was greater than that reported in previous studies and showed geographical differences. This high prevalence suggests that a considerable amount of cases of hepatitis B occurs perinatally and through contact with carriers in the general population. Vaccination of newborns of high-risk pregnant women should be considered.

Adult↗
PubMedDate not supplied

Environmental exposure of commuters in Mexico City to volatile organic compounds as assessed by blood concentrations, 1998.

OBJECTIVE: To assess the extent of exposure for Volatile Organic Compounds (VOCs) among nonoccupationally exposed commuters in Mexico City. MATERIAL AND METHODS: Blood concentrations of benzene, toluene, ethylbenzene, m-/p-xylene, o-xylene and methyl tert-butyl ether were determined on samples collected from participants after the morning commute. RESULTS: Median blood concentrations of benzene (0.11 microg/l), ethylbenzene (0.081 microg/l), m-/p-xylene (0.32 microg/l) and toluene (0.56 microg/l) in the Mexico City participants were all approximately two times higher than in a nonsmoking subset of the Third National Health and Nutrition Examination Survey population of the United States. On the other hand, median VOC blood levels were similar to medians observed in other studies involving commuters in specific U.S. cities, despite the fact that only half the Mexico City study participants commuted by personal vehicles compared with all U.S. commuters. CONCLUSIONS: These results reflect the extent of the air pollution problem in Mexico City. The surrounding topography exacerbates the problems caused by heavy vehicular traffic, poor emission-control devices on older vehicles, and poor maintenance practices. Elevated levels of gasoline components in the blood of nonoccupationally exposed commuters emphasize the need for regulatory initiatives and mass-transit options to reduce hydrocarbon emissions and thus reduce the risk for nonoccupational exposure for the residents of Mexico City.

Adult↗