Novel Lead Testing Device with a Lower Threshold
While science’s ability to determine health effects occurring from lower and lower levels of lead in the blood has increased, an ideal blood testing method for mass use on children that is sensitive enough to detect those levels has not appeared. One under development by researcher Chenyu Wang and their team seems promising, however. Problems with previous mass testing methods are that they are either too costly to be feasible as with atomic absorption spectrometry or inductively coupled plasma mass spectrometry; not sensitive enough as with anodic stripping voltammetry; or take too long as with colorimetric techniques (Wang et al., 2016, p. 1). Wang’s team has innovated beyond these types of techniques by using a thin ultrasensitive conducting material called graphene which can be used sparingly as a very small biosensor that does not require the time-consuming labels that colorimetric techniques use (Wang et al., 2016, p. 2). Wang’s team was able to use their Graphene based FET aptasensor to measure blood lead levels at or below 3.75ng/dL (Wang et al., 2016, p. 6), three levels of magnitude below what is currently set as the threshold lead detection of the CDC at 10 μg/dL (Landrigan, 2000, p. 530).
However, this potential new technology by necessity brings up an older debate. Screening of children of any kind, even at extremely low levels as the potentially aptasensor allows for, at its core admits that children are going to be exposed. If they were not exposed, then screening would not be necessary. Primary prevention, removal of lead from the environment that children will be in, has been favored by many scientists, because this strategy prevents exposure in the first place. For example, the American Academy of Pediatrics put out a statement in 1987 that said that “‘children are used as biologic monitors for environmental lead’” (as cited by Markowitz and Rozner, 2013, p. 132) which is unethical because the goal should be to prevent childhood exposure instead of using children as indicators of how the lead levels are in an environment (Markowitz and Rozner, 2013, p. 132).
The CDC in 1987 agreed saying that lead dangers should be entirely nullified which they believed was becoming a consensus from both leading medical personnel and state bureaucrats (Ibid). Bruce Lanphear echoed this sentiment in his work, stating that “because lead exposure is cumulative and its detrimental effects are irreversible, any strategy that is limited to screening children after an exposure has occurred is flawed. Although there continues to be a need to refine screening strategies…it is more critical to expand our efforts to identify and eliminate residential lead hazards before children are unduly exposed,” (1998, p. 1617). Dr. Carol Angle and her colleagues’ work to determine how lead exposure was entering the diets of Omaha’s children in the 90s was a part of this debate in that it was focused on how exposure was occurring and therefore how it could be prevented further, based on the strides that were already made in primary prevention in the 20th century (Manton et al., 2005, p. 8995).
Landrigan, P. J. (2000). Pediatric lead poisoning: is there a threshold? Public Health Reports, 115(6), 530.
Lanphear, B. P. (1998). The Paradox of Lead Poisoning Prevention. Science, 281(5383), 1617-1618. https://doi.org/10.1126/science.281.5383.1617
Manton, W. I., Angle, C. R., & Stanek Krogstrand, K. L. (2005). Origin of Lead in the United States Diet. Environmental Science & Technology, 39(22), 8995-9000. https://doi.org/10.1021/es051145e
Markowitz, G. E., & Rosner, D. (2013). Milbank Memorial Fund(Eds.), Lead wars the politics of science and the fate of America's children. Berkeley: University of California Press; New York : Milbank Memorial Fund.
Wang, C., Xinyi, C., Ying, L., Hongbo, L., Lei, H., Jun, B., Jun, L., Lena, Q. M., Wei, Z., Yi, C., Baigeng, W., and Feng M. (2016). A label-free and portable graphene FET aptasensor for children blood lead detection. Scientific Reports 6, (21711). https://doi.org/10.1038/srep21711