Buelna Genoveva, Riffat Rumana
Facultad de Enfermería Laredo, Universidad Autónoma de Tamaulipas, Nuevo Laredo, México.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2007 Aug;42(10):1379-90. doi: 10.1080/10934520701480383.
The international border region of the Rio Grande faces severe environmental and economic challenges. Contamination and degradation of its fragile lotic environments are mainly due to stresses from rapid population growth and unchecked industrial development. This study evaluates the water quality of the Rio Grande in the area of Nuevo Laredo, Mexico and Laredo, Texas, USA, in terms of physical, chemical and bacteriological parameters, as well as total metals, organochlorine pesticides, volatile organic compounds (VOC), semi-volatile organic compounds (SVOC) and radioactivity. Surface water samples were collected at 3 sites along the river. Two additional non-river sites (potable water and residual water) were studied for a better assessment of water quality in the region. Three series of samples were taken every other day during one week (November 3 to November 8, 2005) from the five sampling sites. Levels of oil and grease in all the river samples exceeded the limits established by Mexican regulations. Concentrations of aluminum above the permissible limits for source of drinking water and for quality for protection of freshwater biota were also found in all of the river sites. A number of unregulated elements (Cd, Sr, Mg, Na, Fe, Si, Li and K) appeared in the river samples. The average concentrations of Ba and Na in the potable water samples were below the permissible limits. Ca, Sr, Mg and Si were also found but are not regulated. The majority of the organic compounds studied in both the river and in residual water samples was below detection limits. In all the potable water samples, bromodichloromethane and dibromochloromethane were found above their limit of quantitation (LOQ), but these compounds are not regulated. This preliminary study suggests the need for consistent periodic monitoring to track the environmental status of the Rio Grande.
格兰德河的国际边境地区面临着严峻的环境和经济挑战。其脆弱的河流环境受到污染和退化，主要是由于人口快速增长和工业发展失控带来的压力。本研究从物理、化学和细菌学参数，以及总金属、有机氯农药、挥发性有机化合物（VOC）、半挥发性有机化合物（SVOC）和放射性等方面，评估了墨西哥新拉雷多和美国得克萨斯州拉雷多地区格兰德河的水质。在沿河的3个地点采集了地表水样本。另外还研究了两个非河流地点（饮用水和残留水），以便更好地评估该地区的水质。在2005年11月3日至11月8日的一周内，每隔一天从5个采样点采集了3组样本。所有河流样本中的油脂含量均超过了墨西哥法规规定的限值。在所有河流采样点还发现，铝的浓度超过了饮用水源和保护淡水生物群质量的允许限值。河流样本中出现了一些未受监管的元素（镉、锶、镁、钠、铁、硅、锂和钾）。饮用水样本中钡和钠的平均浓度低于允许限值。还发现了钙、锶、镁和硅，但它们不受监管。在河流和残留水样本中研究的大多数有机化合物低于检测限。在所有饮用水样本中，溴二氯甲烷和二溴氯甲烷的含量超过了定量限（LOQ），但这些化合物不受监管。这项初步研究表明，需要进行持续的定期监测，以跟踪格兰德河的环境状况。
