The Exposome

The World Around Us, the Biology Within

Every day, we exchange signals with the world—through the air we breathe, the scents we encounter, the food we taste, and everything that touches our skin.

Within us, our genes, metabolism, hormones, nervous system, and immune system continuously respond to these external signals. Over time, this dialogue shapes our skin, emotions, and overall well-being.

This is why we focus on the exposome:
to understand how everyday exposure becomes a biological response—and how each interaction can become a more positive influence on human health.

Exposome diagram connecting environmental factors, lifestyle factors, and internal biology around a human profile

Exposome Science

Integration of External and Internal Factors and Exposure Dynamics in Determining Human Health

Sunlit city with traffic, industrial emissions, and green spaces

External Exposome

Environmental Exposures

Woman hiking in the mountains and carrying a water bottle

Internal Exposome

Lifestyle & Individual Factors

A man shown across four moments from daylight to evening

Exposure Dynamics

Exposure Over Time

Personal Exposome

An individual’s unique exposure profile across space and time.

External(Environmental)
Internal(Individual)
Exposure Dynamics(Temporal)
Personal Exposome

Exposome Biological Impact Index (EBII)

Toward a Quantifiable Reference for Exposome-Driven Biological Impact

A&S focuses on understanding how the external exposome influences human health and biological functions. From environmental and lifestyle factors to biological responses and health status, these elements form complex and dynamic relationships. To better understand these pathways and mechanisms, A&S continues to develop relevant research methods and science-based solutions.

As a first step, A&S is working toward the development of the Exposome Biological Impact Index (EBII). EBII aims to integrate multiple exposure and biological response factors through scientific models and algorithms, translating them into a quantifiable reference index for assessing, understanding, and managing the dynamic biological impact of the exposome.

Exposome Load

  • Environmental
  • Lifestyle
  • Chemical
  • Physical
  • Biological
  • Social
Traffic and a city skyline

Susceptibility

  • Genetics
  • Epigenetics
  • Age
  • Biological factors
  • Health status
  • Comorbidities
DNA helix beside an older person's face

Resilience

  • Detoxification
  • Immune defense
  • Repair capacity
  • Metabolic flexibility
  • Recovery capacity
  • Antioxidant defense
Immune cell and mitochondrion illustration

Time

  • Duration
  • Frequency
  • Timing
  • Cumulative burden
  • Life course stage
People at different stages of life

EBII

Quantifiable
Reference Index

External Exposome

External Exposome

Environmental Exposures

All non-genetic exposures originating outside the individual.

Woman walking through a city surrounded by traffic and industrial emissions
Traffic on a sunlit city street

Physical Environment

Air · UV · Noise · Climate

Environmental worker inspecting a water sample near an industrial site

Chemical Environment

Pollutants · Metals · Pesticides

Pollen released from flowering tree catkins

Biological Environment

Pathogens · Allergens · Microbiota

People commuting through a busy urban street

Built & Social Environment

Urban life · Work · Indoor environment

Gloved hand holding a dish of microplastic particles near water

Other Exposures

Microplastics · Water · Food contaminants

Internal Exposome

Internal Exposome

Lifestyle & Individual Factors

Endogenous and modifiable factors within the individual.

Woman wearing a sensor consulting a clinician beside a health-monitoring screen
Everyday lifestyle scenes: preparing food, running, sleeping, socializing, taking medication, and experiencing stress

Lifestyle & Behavioral Factors

Diet & Nutrition · Physical Activity · Sleep · Psychological Stress
Smoking · Alcohol · Medications · Social Interaction

Internal Biological State & Processes

Innate Factors · Genetics & Epigenetics · Immune Function · Inflammation
Oxidative Stress · Metabolism · Endocrine Status · Gut Microbiome · Neuroendocrine Function

Biological research scenes: blood sample, microscopy, three generations of women, laboratory cultures, and analytical testing
Exposure Dynamics

Exposure
Dynamics

The Third Dimension
of Exposome Science

An Original A&S Framework

Temporal aspects of exposure have long been discussed. The distinctive contribution of A&S founder Dr. Yen is to formalize Exposure Dynamics as an independent, core third dimension alongside External and Internal Exposome.

This dedicated framework explains and quantifies how exposures vary in intensity, persist over time, recur, occur at critical moments, interact as mixtures and accumulate across the lifespan.

The same woman in the city across morning, daytime, evening, and night
From a Single Exposure to a Lifelong Biological History

Exposure Dynamics

Six Dimensions of Exposure Over Time

Woman in city streets with increasing traffic and air pollution

Intensity

How much

Dose / Concentration

Construction worker at the same site from morning through daytime to night

Duration

How long

Length of time

Woman commuting, using her phone, and working at a laptop during recurring daily activities

Frequency

How often

Occurrences per unit time

The same city skyline at dawn, daytime, dusk, and night

Timing

When

Time of day · Week · Season · Life stage

Woman in a smoky social setting with a drink beside a street with traffic emissions

Mixture

What combination

Co-exposures & correlations

A woman shown at three ages across her lifespan

Cumulative Exposure

Over the lifespan

Time-weighted accumulated dose

Personal Exposome

Personal Exposome & Human Health

Health effects unfold in sequence—and can reinforce the exposures that shaped them.

  1. Woman in traffic surrounded by scenes of poor sleep, fast food, stress, and industrial pollution

    Personal Exposome

    Accumulated external, internal and temporal exposures

  2. Woman with irritated skin beside laboratory testing of biological responses

    Biological Response

    Inflammation · Oxidative stress · Neuroendocrine and metabolic change

  3. The same woman shown at three ages along an altered aging trajectory

    Altered Aging Trajectory

    Reduced resilience · Impaired repair · Loss of homeostasis · Functional decline

  4. An older woman receiving care from a doctor and nurse in hospital

    Health Outcomes

    Progressive effects on physical, mental and long-term wellbeing

Exposures AccumulateBiology RespondsAging Trajectory ShiftsHealth Changes

From Personal Exposome to Biological Impact

An Upstream-to-Downstream Cascade Across Biological Levels

  1. Personal Exposome

    Woman in an urban environment with traffic, sleep disruption, and lifestyle exposures

    External exposures · Internal factors · Exposure dynamics

    Physical · Chemical · Biological · Social · Lifestyle

  2. Exposure Routes & Absorption

    Exposure through breathing, drinking water, and skin contact with a surface

    Inhalation · Ingestion · Dermal & mucosal uptake

    Determines the biologically effective dose

  3. Core Biological Mechanisms

    Microscopic tissue, molecular processes, laboratory samples, and cellular analysis

    Oxidative stress · Inflammation

    Endocrine, immune & metabolic dysregulation

    DNA damage · Epigenetic change

  4. Multilevel Biological Impact

    Cells and tissue alongside a researcher assessing organ-system imaging

    Cellular stress & damage

    Tissue dysfunction · Organ-system effects

    Altered aging trajectory

  5. Potential Adverse Health Outcomes

    Older woman receiving medical care in a hospital bed

    Acute effects · Chronic conditions

    Developmental & reproductive impacts

    Reduced physical & mental wellbeing

    Compromised healthy longevity

Biological impact reflects both exposure burden and individual susceptibility.

Exposome Biological Impact Index (EBII)

The EBII Conceptual Model

Four Interacting Dimensions Shape Estimated Biological Impact

Traffic and industrial emissions across a city

Exposome Load

Physical · Chemical · Biological
Social · Lifestyle · Sensory

Higher exposure Higher E

An older woman coughing beside a younger woman in an urban environment

Biological Susceptibility

Genetics · Epigenetics · Age
Baseline health · Existing conditions

Higher susceptibility Higher S

Immune cells interacting with pathogens

Biological Resilience

Repair · Immune defense · Detoxification
Metabolic flexibility · Recovery capacity

Protective capacity

Higher resilience Higher R

The same woman shown through changing exposure conditions over time

Time

Duration · Frequency · Timing
Cumulative burden · Life course stage

Longer exposure time Higher T

Conceptual Operational Model

EBII=E×S×TR+ε
E
Exposure Load
S
Susceptibility
R
Resilience
T
Time

ε is a small constant included for numerical stability.

A first-order conceptual approximation. Real-world relationships may be nonlinear, dynamic and feedback-dependent.

From EBII to Biological Impact

Interpreting Estimated Impact Across Biological Levels

A tired man having a health assessment in a clinical setting

Higher Estimated EBII

Greater Estimated Biological Impact

  • Higher exposure load
  • Higher susceptibility
  • Longer exposure time
  • Lower biological resilience
VS.
A man hiking outdoors beside a lake and mountains

Lower Estimated EBII

Lower Estimated Biological Impact

  • Lower exposure load
  • Lower susceptibility
  • Shorter exposure time
  • Higher biological resilience

Biological Impact Across Levels

  1. Molecular

    Microscopic illustration of molecular interactions

    DNA damage · Oxidative stress · Epigenetic change

  2. Cellular

    Cells viewed under magnification

    Inflammation · Senescence · Impaired signaling

  3. Tissue & Organ

    Tissue microscopy alongside a clinician reviewing organ scans

    Tissue dysfunction · Multi-system effects

  4. Whole Body

    A man discussing his wellbeing with a clinician

    Reduced resilience · Recovery · Adaptability

  5. Potential Outcomes

    An older man speaking with a healthcare professional

    Healthspan · Wellbeing · Function · Quality of life