Moss biomonitoring of air pollution with potentially toxic elements in the Kumanovo Region, North Macedonia

Mortality and heavy metals environmental exposure: a study in dogs

Introduction

Dogs are human companions and share environmental conditions with their owners. Epidemiological studies have shown that dogs seem to be good sentinel animals for the association of diseases and/or mortality provoked by chronic exposure to heavy metals (Cd, Pb).

Methods

In the present work, we analyze the registered death cases and population from the National Canine Registry from 2020 to 2022, involving a dog population of 582,564 and 17,507 deaths. The mortality rate in male and not-purebred dogs is higher than in female and purebred dogs, respectively. The mortality cases were cross-referenced with the environmental pollution data relating to the concentration of Cd and Pb detected, between 2012 and 2022, in the various municipalities of the Liguria region. We then calculated SMR (Standardized Mortality Rate) throughout the region and found that mortality increases from the eastern to the western Ligurian coast.

Results and discussion

We observed that the most polluted areas present the highest SMRs (IRR = 1.36, 95%CI: from 1.31 to 1.41). Considering dog ages, we found that mortality in young dogs is not affected by pollution, while mortality in old dogs (10-20 years old) is heavily affected by it (IRR = 8.97, 95%CI from 8.09 to 9.93). In conclusion, the data suggest the importance of canine health and biomonitor studies and provide a basis for future research involving both animal and human health.

Assessment of atmospheric heavy metal pollution in Qinghai-Tibet Plateau: Using mosses as biomonitor

Atmospheric heavy metal (HM) pollution may pose a significant threat to the fragile ecosystem of Qinghai-Tibet Plateau (QTP). To investigate potential atmospheric HM pollution within the QTP region of China, mosses, along with other higher plants and soil, were collected from 33 sites for heavy metal measurement. The concentration ranges of Zn, Pb, Cd, and Cu in mosses were 6.07-69.9, 5.36-23.9, 0.60-1.05, and 14.4-50.5 mg·kg-1 (dry weight), respectively, significantly higher than those in other higher plants, except for Zn. The spatial distribution of relative concentrations (RCs; moss to top soil) of HMs varied considerably, indicating distinct differences in atmospheric Zn and Cu pollution levels between the northern and southern QTP. This study first reported that moderate regional atmospheric Cu pollution, primarily due to large-scale mining in recent years, had occurred, particularly in southern QTP. Pb also presented slight pollution due to anthropogenic activities. However, Cd showed almost no atmospheric pollution, while Zn concentrations were relatively high in southern QTP. Although less severe than atmospheric pollution levels in Chinese inland or coastal cities, the atmospheric pollution of Pb and Cu in QTP indicated by mosses were far more severe than global background areas, or even worse than most European cities.