Health impact, measurement limitations

Data needed include expected variations in conditions costs of materials, labor, equipment, and utilities disposal limitations sources legal definitions and restrictions environmental impact measures and numerical values for the criteria. For all the species involved in the process, we need physical and thermodynamic data, and such reactivity and safety properties as flammability, corrosivity, abrasiveness, and propensity for dust explosions of solids, stability, environmental persistence and health indicators such as the LDjg, carcinogenicity, mutagenicity, and toxicity and those listed in Table 16.16. 

Much like the means for determining the health impact and risks associated with exposure to nanoparticles, the research into the characterization of nanoscale particles is in its infancy. In addition, it is recogiuzed that moifitoring instrumentation used in the field requires improvement in both portability and measurement sensitivity. Table 9.1 provides a summary of nanoparticle measuranent techniques that are either currently in the developmental stages or have already been impl ented in the nanotechnology industry. The table includes the method, the metric measured and the major capabilities and limitations of each. 

Despite the environmental eoneerns about some of the chemicals used in plastie manufacture, it is important to emphasize that evidence for effects in humans is limited, and there is a need for further research - particularly for longitudinal studies to examine temporal relationships with chemicals that leach out of plastics (Adibi et al. 2008). In addition, the traditional approach to studying toxicity of chemicals has been to focus only on exposure to individual ehemicals in relation to disease or abnormalities. However, because of the eomplex integrated nature of the endoerine system, it is critical that future studies foeus on mixtures of ehemieals to which people are exposed when they use eommon household produets. For example, 80 per cent of babies in a study conducted in the United States were exposed to measurable levels of at least nine different phthalate metabolites (Sathyanarayana et al. 2008), and the health impacts of the cumulative exposure to these chemicals need to be determined. An initial attempt at examining more than one phthalate as a contributor to abnormal genital development in babies has shown the importance of this approach (Swan 2008). 

There are a number of traditional and new control measures to protect consumers from food-borne parasites. Ionizing radiation is one of the new technologies to control or limit the impact of a number of food-bome parasites on public health [10]. 

To assess the impact of dairy food on health, measures to objectively assess intake are critical. As stated earlier in this chapter, one of the major limitations of nutrition research is the utilization of self-reported dietary intake data. An increase in awareness of healthy eating patterns as a result of advertising and nutrition education may exacerbate bias associated with self-reported dietary intake methodology (Johansson et al., 1998). This is especially the case of at-risk groups. For example, obese people are more prone to underreporting dietary intakes (Livingstone and Black, 2003). 

David Eddy at Duke University has written extensively on the problems and potential solutions related to pharmaceutical performance measurement systems. According to a U.S. survey, the most commonly perceived problems with pharmaceutical performance measurement systems are limitations with billing and administrative databases, lack of time to review summary data by physicians, and incomplete data. Other limitations include risk adjustment (what if my practice has sicker patients), overreliance on administrative (claims) data rather than clinical data (therefore lacking key patient outcomes), patient individuality and variation in medical practice, and lack of capacity for taking into account a discipline-specific rather than a whole programs-oriented CQI approach. There has also been some debate on the reliability of performance measurement systems to assess the true impact of physician care on the quality of health care.t ... 

Current health research is attempting to address the issue of whether or not there is a threshold for the impact of lead upon child development. Although it is often claimed that there is no threshold for the effect of lead upon child intelligence , this somewhat hyperbolic statement should more appropriately be viewed as reflective of limitations inherent in current neuFobehavioral research. The effects of lead at low levels of exposure are extremely subtle and current analytical techniques, both in the measurement and statistical analysis of psychometric impacts, are unable to discriminate the presence or absence of effect thresholds (5). For some, the level of concern thus represents a practical threshold for the setting of public health policy. If effects exist below this level, they are likely quite small in magnitude. 

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