ABSTRACT
Among its different activities the Mexican Health Ministry (SSA) promotes: 1) the specification of biological standards for the Mexican population; 2) mechanisms for early detection of physiopathological changes and 3) development of the appropriate technology as a basis for primary health care. As part of this program we studied a random sample of students at the "Colegio de Bachilleres" of Cuajimalpa a suburban area of Mexico City, situated at 2800 m above sea level, part of the equipment used was produced at the Center for Development and Technological Applications (CE-DAT), an agency of SSA. Height, weight, heart rate (HR), systolic and diastolic blood pressures (SBP/DBP) were measured at rest in sitting position, standing up and walking on a treadmill. The results show a population with similar physical characteristics to those described for other populations in Mexico, with HR values within a homogeneous distribution, except for three subjects with rates larger than 2 standard deviations (SD). At standing up, women showed an orthostatic reflex of 27 beats/min and men of 22 beats/min. At the beginning of the exercise, the HR curve becomes more homogeneous, showing a discrete ascending slope with a low correlation coefficient, suggesting low physical capacity of the studied population. As exercise continued, some subjects showed a low increment of HR, giving values differing by 2 SD. Five women and three men had resting SBP values lying 2 SD out of the mean values of the sample. During exercise, SBP increases 28 mmHg as average. Notwithstanding the low cardiac response, the time spent on the treadmill lies within the levels considered as good and, even, excellent, on the table of the National Institute of Cardiology. We discuss new procedures to analyze instantaneously the HR and the pressoreceptor reflex as well as their functional significance.
Subject(s)
Altitude , Exercise Test , Adolescent , Adult , Female , Humans , MaleABSTRACT
Both the altitude of Mexico City (D.F.) and the increase in atmospheric pollutants make it important to establish parameters of comparison for cardiovascular variables, such as heart rate (HR) and blood pressure (BP). The epidemiological transition occurring in Mexico is increasing the need for human and physical resources at the first level of health care in order to perform early diagnoses of cardiovascular disorders among the population. Heart rate, systolic and diastolic blood pressures (SBP, DBP) were recorded under diverse conditions (seated, standing, performing 30 sit-ups, and then standing and seated after the sit-ups) in 235 inhabitants of Milpa Alta (a suburb of Mexico City). The procedures and equipment used were designed and produced at the Center for Development and Technological Applications, Ministry of Health. The following results were found: HR decreases with age and body surface. Likewise, the HR increase due to exercise is lower with increasing age and larger body surface and its return to resting levels is slower. SBP and DBP magnitude is directly related to body surface. In women an increase of body weight was found to be significantly related to a higher SBP. The orthostatic reflex (OR) decreases with age and body surface. The descending slope is higher in women than in men. We propose that the study of OR could provide better information for predicting cardiovascular changes. The described procedures can be performed with the physical and human resources available at the Health Centers. The extension of this type of applied research to first level health care centers would allow the country to respond efficiently to the epidemiological transition.
Subject(s)
Blood Pressure , Heart Rate , Adolescent , Adult , Age Factors , Aged , Body Weight , Child , Child, Preschool , Female , Humans , Male , Mexico , Middle Aged , Physical Exertion , Posture , Sex Factors , Urban PopulationABSTRACT
With a view to evaluating a small-scale water disinfection system based on production and application of oxidizing gases, the level of equivalent residual chlorine and the degree of contamination by fecal and total coliform bacteria was assessed at various points in the drinking water system of a Mexico City hospital before and after installation of the disinfection equipment. Tests done in May and June 1989, prior to installation of the equipment, showed that residual chlorine concentrations were lower than the national standard in most of the samples and that a sizable portion of these samples were also contaminated with fecal and total coliform concentrations exceeding national standards. After installation of the disinfection system at the main inflow to the hospital's drinking water supply in August 1989, the equivalent residual chlorine concentrations were found adequate and no coliform bacteria were detected. These results indicate that the oxidant mixture generated by the newly installed system was effectively disinfecting the water.
