Exploring the effects of environmental toxins from air pollution on chronic kidney disease

Recent reviews of the impact of air pollution on human health have shown scientific evidence for the detrimental effects of air pollutants, including environmental toxins which may become blood-borne and translocate to tissues such as the liver, brain and kidney. Atmospheric pollution deposition from traffic and brake wear emissions have been discovered to be important potential sources of toxic metals including arsenic (As), cadmium (Cd), iron (Fe), molybdenum (Mo), lead (Pb), tin (Sn), antimony (Sb), Uranium (U) and Zinc (Zn). Chronic kidney disease (CKD), a collective term for many causes of progressive renal failure, is increasing worldwide due to ageing and a general increase in obesity and diabetes. CKD attributed to unknown aetiology (termed CKDu) is an increasing issue globally with the occurrence of geographic clusters appearing to suggest potential underlying environmental causes of CKDu. This study uses data from the UK Renal Registry including Chronic Kidney Disease of uncertain aetiology (CKDu) to investigate the impact of environmental toxins including air pollution data on human health. Using an urban soil geochemistry database of total element concentrations of potentially toxic elements (PTEs), we examine the spatial statistical relationship between Standardised Incidence Rates (SIRs) of CKDu with environmental toxins and air pollution data. A compositional data analysis approach is used with the use of balances (a special class of log contrasts) to find an elemental balance associated with CKD and CKDu. Using a compositional data analysis approach, informed by the selected PTEs and air pollution balance approach, regression analysis (using glm with log link) reveal a statistically significant correlation between CKD for all SIRs for the age group >16 years and the identified balance of Mo/Zn (significance level of 0.001) and the MDM domains of employment, income and health (significance levels of 0.001, 0.01 and 0.05 respectively). Results from the compositional balance approach indicate an association with the air pollutants SO2, CO, Benzene, PM10 and PM2.5. However, the relationship between CKD for all SIRs >16 years and these air pollutants was not found to be statistically significant. The findings from this work allow a greater understanding of the link between human health and environmental toxins from anthropogenic sources including air pollution.