Water quality measurement in regions of poor sanitation

由于饮用水水源(溪流、水井)中的病原体(来自人类和动物排泄物)导致健康不良，微生物水媒疾病仍然是全世界水界的一个重大关切。这些问题对发展中国家的穷人造成不成比例的影响。例如，11亿人无法获得安全饮用水供应，26亿人得不到改善的卫生服务。撒哈拉以南非洲的情况最为严重，42%的人口没有得到改善的水，的人口没有得到改善的卫生设施。联合国千年发展目标的目标是到2015年将无法获得安全饮用水的人数减半，因为全球因水、环境卫生和个人卫生相关疾病造成的疾病负担约为8200万残疾调整生命年(DALY)。这一关键的公共卫生问题将受益于改进的检测方法。获取粪便大肠菌群的标准计数需要30多个小时，并且需要熟练的培训和实验室条件来准备样品。因此，它们的使用是有问题的，而且很少使用，尽管快速的饮用水质量检查对于防止疾病迅速传播和死亡是必不可少的。此外，这些技术超出了迫切需要饮用水和卫生设施改善的最贫穷社区的能力范围。针对这一问题，我们提出了一种新颖的解决方案，即通过测量饮用水荧光来解决这个问题。所有的水都是荧光的，尽管人眼对适当的波长不敏感，所以荧光对我们来说是不可见的。然而，现成的设备可以检测到这种荧光，大量研究表明，水荧光特别擅长识别粪便污染(包括人类和动物)。这项建议的重点是，在所有类型的粪便衍生水域中，在220-240 nm或270-280 nm激发下，广泛观察到340-370 nm处发出的本征荧光；通常称为荧光峰T，或类色氨酸荧光。我们将开发一种荧光传感器，使其能够实时、手持地检测饮用水的微生物质量，特别是在发展中国家普遍存在的卫生条件差或没有卫生条件的地区，以及在救灾期间。饮用水荧光筛查的优点是分析速度快。在不到1分钟的时间内就能得到结果，大大改进了现有的大肠菌群计数技术。这项技术使用廉价的现成设备(荧光分光光度计)，这些设备是便携式的(从4x4车辆或临时野外实验室的后部)。最后，有能力由个别社区的非专家对结果进行专家解释以及简化图形解释，因此有能力让贫穷的用水者自己参与技术的应用。各级利益攸关方的参与都将成为可能。

Microbiological waterborne disease remains a significant concern for the world wide water community, as pathogens (from human and animal wastes) in drinking water sources (streams, wells) cause ill health. These issues disproportionately affect the poor in developing countries. For example, 1.1 billion people do not have access to safe drinking water supplies and 2.6 billion are without access to improved sanitation services. Conditions are most severe in sub-Saharan Africa where 42% of the population is without improved water and 64% are without improved sanitation. The UN Millennium Development Goals aim to halve the number of people without access to safe drinking water by 2015, as the global disease burden of water, sanitation and hygiene related diseases is approximately 82 million disability-adjusted life years (DALYs). This critical public health issue would benefit from improved detection methods. Obtaining standard counts of faecal coliforms takes in excess of 30 hours and needs skilled training and laboratory conditions for the preparation of samples. Consequently, their use is problematic and infrequent, even though rapid drinking water quality checks are essential to prevent rapid disease spread and death. Also, these techniques are beyond the reach of the poorest communities that are in urgent need of drinking water and sanitation improvements. We propose a novel and innovative solution to this problem by measuring drinking water fluorescence. All water fluoresces, although the insensitivity of the human eye to the appropriate wavelengths renders fluorescence invisible to us. However, off-the-shelf equipment can detect this fluorescence, and a large body of research has demonstrated that water fluorescence is particularly good at identifying faecal contamination (both human and animal). The focus of this proposal is derived from the widespread observation of intrinsic fluorescence emitted at 340-370 nm under excitation at either 220-240 nm or 270-280 nm in all types of faecal derived waters; commonly referred to as fluorescence peak T, or tryptophan-like fluorescence. We will develop a fluorescence sensor that will permit the real-time, hand held sensing of the microbiological quality of drinking water, particularly in areas of poor or no sanitation as widely found in developing countries and during disaster relief scenarios. Advantages of fluorescence screening of drinking water include rapid analysis time. Results are available in less than 1 minute, significantly improving on existing coliform count technology. The technique uses cheap, off-the-shelf equipment (fluorescence spectrophotometers) that is portable (from the back of 4x4 vehicles or temporary field labs). Finally, there is the ability to have both expert interpretation of results as well as simplified pictorial interpretation by non-experts in individual communities and therefore have capacity to involve poor water users themselves in the application of the technology. Stakeholder participation at all levels will be possible.