Zain Alabdain Alqattan

Graduate Student, PhD

Mentor:

Dr. Monica Ramirez-Andreotta

Department:

Environmental Science

Abstract:

Between Environmental Injustice and Compound Climate Events: Lead Source1 Apportionment in Rural, Copper Mining Communities

After a sequence of natural disasters in select mining communities in Arizona, USA, community members raised concerns about metal(loids) exposure and origin in their environment. To address these concerns, non-residential soil (0-2cm, 2-15cm, and 15-30cm), household soil (0-2cm), and indoor and outdoor dust samples were analyzed for metal(loids) concentration and lead isotopes via inductively coupled plasma mass spectrometry. In parallel, an in-depth literature review was conducted to evaluate the sources of lead in the partnering environmental justice (EJ) communities. Spearman's correlation and principal component analysis were used to investigate the co-occurrence of metal(loids) associated with lead. The results demonstrated a strong correlation between Pb and mining activity in the non-residential locations as well as a co-occurrence with Arsenic, Copper, Cadmium, and Zinc in soil depths of 0-2 cm and in 2-15 cm, and to lesser extent, in 16-30 cm. The outdoor household dust was impacted by a mixture of Pb sources and was associated with metal(loids) from natural/background and anthropogenic sources, whereas indoor Pb dust had no clear association. While the wildfire did not have a high impact on the non-residential locations, 25% of household samples were aligned with the wildfire Pb isotopic ratio/fingerprint. The Positive Matrix Factorization indicates the flood’s ability to remobilize metal(loids) from neighboring resource extraction sites to the households’ locations. Currently there is no established Pb isotopic ratio composition for wildfires in AZ; this study lays the foundation for understanding the complex relationship between the myriad of lead sources in our environment, wildfires, and flooding.