A Comparison of Burden of Disease from Toxic Waste Sites with other Recognized Public Health Threats in India, Indonesia and the Philippines

Exposure to chemicals from toxic waste sites is a serious and insufficiently examined contributor to the global burden of disease.1 Although toxic waste sites have been well investigated in many developed countries, the prevalence of such sites and their impact on human health have not been well documented in lowand middle-income countries (LMICs), where risks attributable to environmental pollution are generally higher than in developed nations. This difference is likely due to limited controls on emissions and exposure, poverty, lack of investment in modern A Comparison of Burden of Disease from Toxic Waste Sites with other Recognized Public Health Threats in India, Indonesia and the Philippines


Introduction
Exposure to chemicals from toxic waste sites is a serious and insufficiently examined contributor to the global burden of disease. 1 Although toxic waste sites have been well investigated in many developed countries, the prevalence of such sites and their impact on human health have not been well documented in low-and middle-income countries (LMICs), where risks attributable to environmental pollution are generally higher than in developed nations. This difference is likely due to limited controls on emissions and exposure, poverty, lack of investment in modern Blacksmith Institute for a Pure Earth has compiled DALYs from different toxic chemicals at waste sites, including the 8 chemicals analyzed in this paper: aldrin, asbestos, cadmium, chromium VI, dichlorodiphenyltrichloroethane (DDT), lead, hexachlorocyclohexane (lindane) and inorganic mercury. This information was used by Chatham-Stephens et al. (2013) to calculate the burden of disease from toxic waste sites, in which pooled data for each chemical was published for India, Indonesia and the Philippines. The data for the calculations of the DALYs in these countries was collected through the TSIP. 7 Chatham-Stephens calculated the DALYs for exposure to industrial pollutants for 373 toxic waste sites in India, Indonesia and the Philippines with a methodology that had not been attempted previously by any organization. The YLD and YLL for exposure to each contaminant was calculated through each relevant environmental medium (air, soil and water) by combining estimates of disease incidence from these exposures with population data. For YLD, they used the same method to calculate disease incidence for all chemicals with the exception of lead, given the availability of lead-specific modeling tools and dose-response relationships. Chatham-Stephens multiplied the risk per person by the level of the contaminant in the relevant environmental medium.

Research
Caravanos et al  Nevertheless, DALYs per capita for lead in the Philippines were higher than those for recognized diseases such as breast cancer, leukemia, prostate cancer and appendicitis in the 3 countries. Table 4 shows the distribution of DALYs for injuries and exposure to chemicals at toxic waste sites in India, Indonesia and the Philippines. In India and Indonesia, with the exception of exposure to forces of Caravanos et al

Figure 2 shows the distribution of DALYs per capita (multiplied per 1,000) for exposure to chemicals at toxic waste sites (lead, chromium VI and all chemicals) and some noncommunicable diseases in India, Indonesia and the Philippines. Blue columns indicate India, red columns indicate Indonesia and green columns indicate the Philippines.
nature and collective violence and legal intervention, all injuries estimated by the WHO had higher DALYs than those for chemicals at toxic waste sites.
In the Philippines, inorganic mercury, cadmium and chromium VI had lower DALYs than all injuries. However, lead presented higher DALYs than the majority of injuries and only road injury (728,200 DALYs) and interpersonal violence (828,000 DALYs) presented higher values than lead. Figure 3 graphically illustrates the distribution of DALYs per capita for chromium VI, lead, the sum of all chemicals and injuries in the 3 countries. Lead in the Philippines presented DALYs per capita similar and even higher than many types of injuries, which was contrary to what was found for lead in Indonesia and India. DALYs per capita for lead in the Philippines were similar to those for falls in Indonesia, and interpersonal violence and drowning in India.

Discussion
Our comparison of DALYs from exposure to chemicals at toxic waste sites with other recognized public health threats in India, Indonesia and the Philippines showed that most of the conditions analyzed by the WHO present higher DALYs estimations than those from exposure to toxic chemicals in India and Indonesia. However, in India, the exposure to chromium VI shows higher DALY estimates than many recognized health threats such as multiple sclerosis and some types of cancers. Likewise, in Indonesia, chromium VI and lead present higher DALYs than conditions such as Parkinson's disease and the sum of the DALYs of all chemicals is greater than the estimated DALY for different types of cancers.
The comparison in the Philippines showed that lead has a higher DALYs estimate than the majority of conditions. Exposure to lead presents a larger DALY value than many recognized health conditions, including malaria and HIV/AIDS. These results suggest that lead is an important contributing factor of disease in the Philippines, as has been found in previous studies of lead exposure in that country. 11, 12 However, our results could be influenced by the under-reporting of notifiable diseases and health-related events in the Philippines, which could falsely show sites contaminated with lead to be a bigger problem than in reality.
Our results suggest that of the 8

Figure 3 shows the distribution of DALYs per 1,000 persons for injuries and exposure to chemicals at toxic waste sites (lead, chromium VI and all chemicals) in India, Indonesia and the Philippines. Blue columns indicate India, red columns indicate Indonesia and green columns indicate the Philippines.
Research toxic chemicals analyzed in this study, chromium VI is the pollutant of biggest concern in India, along with chromium VI and lead in Indonesia. Chromium VI has been identified as one of the major pollutants from the tannery industry in Kanpur, India, despite the fact that this industry is required to comply with the regulations of pollution control systems that ban discharging chromium VI into the environment. Some of these limitations include the fact that the screened sites represent only a portion of the total existing sites in these countries; the assignment of only one cancer and one non-cancer health effect to the DALY estimation per chemical; and the analysis of only one chemical per site, although people living near toxic waste sites are often exposed to multiple chemicals simultaneously. One of the most important limitations of the data collected through the ISS is the extrapolation of results of limited environmental sampling to the entire population at risk, given that this causes an estimation of DALYs under the worst-case scenario. In addition, it is important to consider that the model used for DALY calculations is new, and therefore has not been previously assessed by other organizations or researchers. This fact made it impossible to validate the accuracy of the results for DALYs estimation for chemical exposure at toxic waste sites. These limitations and the fact that the number of contaminated sites analyzed differed per country could be responsible for our results showing substantial differences in the impact of each chemical analyzed in this study.

Research
Despite these limitations, this study offers insight into the comparison of the burden of disease for recognized public health threats with the burden of disease from chemical exposure from toxic waste sites. The results of this study should alert policy makers regarding the importance of chemical pollution in developing countries and encourage governments to allocate funds to collect information on hazardous chemicals and to take action on contaminated sites. Surveillance and bio-monitoring of these sites are needed for future studies. Further epidemiological research in this field is necessary to identify statistically significant associations between exposure to chemicals and outcomes at toxic waste sites, which would allow for a better understanding of the burden of disease caused by these sites. 17

Conclusions
This study highlights that the burden of disease expressed in DALYs from chemical exposure at toxic waste sites may be greater than recognized and well addressed health threats such as HIV/AIDS and malaria in the Philippines and multiple sclerosis, Parkinson's disease and some types of cancers in India and Indonesia. Chromium VI constitutes the majority of DALYs from toxic agents in India, while lead has the highest DALYs in the Philippines and Indonesia. Our results call attention to the need for surveillance and bio-monitoring of toxic waste sites, epidemiological analysis of the associations between exposure to toxic chemicals and outcomes, and remediation of chemical contamination in India, Indonesia and the Philippines. Further research should compare the burden of disease from toxic waste sites with other public health threats with DALYs from a single year, given that the databases used for this study came from different years (2012 and 2010). However, despite these limitations, this study promotes public awareness regarding the importance of chemical exposure from toxic wastes sites for the total burden of disease in developing countries.