Road sediment pollution is an emerging environmental issue with a major concern due to its high mobility, especially in urban areas throughout the world. Since sediment settled on the road contain many toxic heavy metals and organic pollutants at high concentrations. More than thousands of persistent organic compounds are present in the road sediment including PCBs, PAHs, BTEX, PAEs, BPA, etc. Multiple anthropogenic sources of this widespread pollution are commonly observed including construction, vehicle traffic, coal combustion, tire wear, paints, and leaded gasoline. Following are major environmental concerns of road sediment pollution and their managing strategies.
1. Why pollution on the road needs special attention?
Road sediment contains wide particle sizes ranging from a few meters to a nanometer. However, the major environmental concern is PM10 (particle size <10 micrometers) and PM2.5 (particle size <2.5 micrometers) since they can reach the tracheobronchial and alveolar region, respectively. Therefore, PM10 and/or PM2.5 in air is a crucial parameter for calculation of Air Quality Index (AQI). The characteristics of road sediments are highly dynamic and variable due to multiple factors including sources, distribution patterns, and environmental conditions. Even the same city has different sediment pollution loads at various locations due to transport mechanisms such as water runoff, traffic, construction, moisture content, and cleanness. In addition, it also varies seasonally. Generally, high concentrations in summer and low in the rainy season are common since it gets washout.
2. Health risk of road sediment pollution
The road sediment has a very high human health risk potential due to multiple exposure routes including inhalation, dermal contact, and ingestion. Mostly it affects the respiratory and cardiovascular systems resulting in many disorders including asthma, mesothelioma, cancer, low birth weight, and adverse effect on other organ systems. Mostly, road sediment has chronic toxicity and does not show immediate health effects. Hence, it can not be ignorable due to the long-term serious impact on human health. The risk from the road sediment depends on exposure duration, exposure route, concentration, and biological factors.
In addition to human health risks, it has a direct negative impact on photosynthesis, soil fertility, road accident, and respiratory disorder in many animals.
3. Management of pollution on the road
Environmental regulation and public awareness is the critical management approach throughout the world. Since the key to all environmental progress and development is public awareness. However, many countries have insufficient environmental regulatory norms and public awareness regarding road sediment pollution. On other hand, road sweeping and vacuuming with flushing is a common practice to remove sediment from the urban area. In many cases, the cleaning frequency does not match the requirement. Whereas rural areas do not have such practices to reduce sediment pollution which increases over time till it gets washout in the rain. Therefore, we all need to understand the health risk and management practices to reduce their exposure to the same. For every pollution, reduction at the source is the most effective and final approach to manage it sustainably. Therefore further improvement of these approaches should be critical to managing road sediment pollution.
Conclusion
Road sediment pollution is adversely associated with multiple chronic human health effects. However, there is a wide gap in effective management practices and risk assessment. As an individual, we all need to minimize our exposure to road sediment to reduce health risks.
