Ecotoxicology and health risk assessment

Intro

Research topics:

• applied ecotoxicology
• waste and recycled materials characterization
• environmental risk assessment

We have to prove that the presence of a substance is a risk.

BS)

Pollution Event: Black Sea Oil Tankers Accident

• oil
• tankers were damaged causing oil spill
• sea water
• fishes, seabirds, algae, mussels
• 15/12/2024

The more the molecule is symmetric, the more is persistent because is more difficult to decompose

Historical need for Ecotoxicologists and Environmental Risk Assessors:

• Society becoming aware of its "environmental mistakes"
• Need to manage/control/regulate/prevent:
  • Soil consumption and degradation
  • Contaminants in the environment
  • Negative effects on humans (and ecosystems)

ES)

Discussing the case studies

1. They stay a lot in this environment; complex and persistent difficult to end-off (speciation drives toxicity)
2. Persistent remain in this media (accumulation)

INTRO

Research topics:

• applied ecotoxicology
• waste and recycled materials characterization
• environmental risk assessment

We have to prove that the presence of a substance is a risk.

[ES] POLLUTION EVENT: BLACK SEA OIL TANKERS ACCIDENT

• OIL
• TANKERS WERE DAMAGED CAUSING OIL SPILL
• SEA WATER
• FISHES, SEABIRDS, ALGAE, MUSSELS
• 15/12/2024

THE MORE THE MOLECULE IS SYMMETRIC, THE MORE IS PERSISTENT BECAUSE IS MORE DIFFICULT TO DECOMPOSE

Historical need for Ecotoxicologists and Environmental Risk Assessors:

• Society becoming aware of its "environmental mistakes"
• Need to manage/control/regulate/prevent:
  • Soil consumption and degradation
  • Contaminants in the environment
  • Negative effects on humans (and ecosystems)

ES] DISCUSSING THE CASE STUDIES

1. THEY STAY ALOT IN THE ENVIRONMENT, COMPLEX AND PERSISTENT DIFFICULT TO END-UP (SPECIATION DRIVES TOXICITY)
2. PERSISTENT REMAIN IN THIS MEDIA (ACCUMULATION)

Ecotoxicology Paradigms

There are several paradigms:

• Dilution Paradigm: assumes that dispersing pollutants will reduce their harm and largely ignores long-term or systemic effects
• Boomerang Paradigm: acknowledges that pollutants can “come back” (persist, accumulate, return, and cause harm), advocating for caution in the production, use and release of contaminants

This paradigm have influenced today's management approach of chemical substances:

• Pollution can follow unknown pathways in the environment and unknown consequences
• Better safe than sorry, prevention over remediation

• Precautionary principle: when there is scientific uncertainty about the potential risks of an action, especially regarding environmental harm or public health, precautionary measures should be taken to prevent harm
  • It argues for limiting the release of these substances into the environment until their effects can be thoroughly studied
  • The more we know about pollution phenomena, the study of pollution phenomena (i.e., Ecotoxicology) can improve understanding of pollution underlying phenomena
• Gaia hypothesis:
  • Living and nonliving components interact
  • Ecosystem resilience: organisms and processes may adapt to minimize negative effects
  • Ecological thresholds: magnitude where contaminants can overwhelm ecosystem resilience

The current needs for ecotoxicology and environmental risk sciences:

• Environmental regulations and techno-industrial progress proceed unevenly

• Novel environmental issues continue to emerge because of a lack of information on environmental behavior of man-made chemicals
• Contaminants of emerging concerns: Flame retardants, Bisphenols, Phtalates, Poli- and per-fluorinated alkyl substances, Pharmaceuticals, Personal Care Products, Micro and nanoplastics

In conclusion:

The need to study pollution event (i.e., the “Ecotoxicology”) resulted from the change in environmental paradigms and consciousness

Expertise in Ecotoxicology is essential for:

• Develop analytical procedures for monitoring occurrence of substances in the environment
• Assess the effects of substances on the ecosystems
• Estimate the risk to reach Ecological Thresholds
• Improve the application of the precautionary principle
• Develop guidelines for management of chemicals and waste

Definitions

The most common definitions of ecotoxicology:

• The science of pollution (Newman 2015)
• The branch of toxicology concerned with the study of toxic effects, caused by natural and synthetic pollutants, to the constituents of ecosystems, animals (including human), vegetable and microbial, in an integrated context (Truhaut, 1977)
• The study of the fate and effects of a contaminant on an ecosystem (Shane 1994)

The fate is the process that determine the:

• Movement: Advection, Dispersion, PARTITION
• Transformation: Biotic or Abiotic Degradation or chemical reactions

• Distribution: Bioaccumulation, Biomagnification within an ecosystem

Factors influencing the fate of a substance:

• Chemical properties (Solubility, Vapor pressure, hydrophobicity, Persistence...)
• Environmental conditions (T, PH and Redox conditions, Soil composition and bacterial biomass, etc.)

FATE: THE PATH OF A CONTAMINANT IN AN ENVIRONMENTAL MEDIA AND WHAT IT AFFECTS IN THE ECOSYSTEMS.

THE EFFECTS are CHANGES (BIOLOGICAL, CHEMICAL, PHYSICAL, BEHAVIORAL...) in organism, population, communities and ecosystem as a result of exposure to a contaminant.

Changes in different levels of Biological Organization, from changes observed from the molecular scale to the ecosystem scale.

Factors influencing the effects of a contaminant:

• EXPOSURE level (dose/concentration and exposure time)
• BIOAVAILABILITY (the fraction of the amount of contaminant that can be absorbed by an organism)
• Mechanism of TOXICITY (Acute/Chronic, Lethal/Sub-Lethal, sites and modes of toxicity...)

So basically everything is totally connected.

To study the ecosystem we can follow the GAIA HYPOTHESIS:

• Biotic-Abiotic interactions: the Biosphere interacts with other Earth's components to stabilize environmental variables and support life
• Ecosystem resilience: adaptation to altered environmental conditions to minimize harmful impacts

It's a multidisciplinary science that operates at different scales of investigation at which can observe the investigated effects.

To fulfill the studies is possible to use the hierarchical approach: