TOOL FOR HUMAN HEALTH

RISK ASSESSMENT STUDY

By

Dr. J.K.MoitraEMTRC Consultants Pvt Ltd, Delhi

(Lab Recognized by Ministry of Environment & Forests)

Workshop On Air And Noise Pollution And Its Effect On Human Health

Organised by Indian Association for Air Pollution Control (Delhi Chapter)

6th July 20131 emtrc

Presentation Outline

o Presentation describes the approach and

methodology of HHRA study applied at 3 different

states in India (Contrasting environmental and socio-

economic conditions)

o Describes the Software Solutions applied for

assessing the risk

o Findings (only sample)

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Human health risk assessment is the process to estimate the nature and probability of adverse health effects in humans who are exposed to chemicals of potential concern (COPC) in contaminated environmental media. 

Human health risk assessment addresses following issues:• Spectrum of health problems that are caused by environmental exposures.

• Chance that people will experience health problems when exposed to different levels of environmental exposures.

• Environmental risks that people are exposed, at what levels & for how long

• People more likely to be exposed to environmental risks because of factors such as where they work, where they play, what they like to eat, etc.

• The level below which some chemicals don't pose a human health risk

Why HHRA Study

The four components of HHRA study includes

Problem formulation: Identification of COPC, characterization of receptors, and identification of exposure pathways.

Toxicity assessment: Identification of potential adverse effects of COPC and determination of the maximum dose that are likely to result in adverse health effects;

Exposure assessment: Quantification of the total dose of COPC received by human receptors via all relevant exposure pathways;

Risk characterization: Comparison of Estimated Exposures with Exposure Limits to provide an indication of whether unacceptable risks are likely to exist in defined scenarios.

Approach to HHRA study

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Human Exposure Pathways

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o Identify the area of study

o Conduct demographic survey using a structured questionnaire (including diet, living and working conditions, income, time-activity pattern, general perception on health issues)

o Quantify the pollutants present in different environmental media to which people are exposed, like ambient air (indoor and outdoor), ground water and surface water, soil and locally grown cereals, vegetables and fruits.

o Estimate the health risk by using approved / standard software (that follows USEPA Guidelines).

o Generate health data of representative population to establish the baseline (engaging qualified medical professionals).

o Suggest preventive and corrective measures to improve the environment.6 emtrc

Methodology of HHRA Study

RISK MODELING CONCEPT

Exposure and Risk are calculated using the USEPA Guidelines and Software Model based on the guidelines.

Two types of risks are considered; carcinogenic & non-carcinogenic risk

Potential to develop cancer is carcinogenic risk. Acceptable exposure levels - concentration levels that represent upper-bound lifetime cancer risk of 10-4 to an adult.

Non-carcinogenic chemicals only cause hazard. Hazard Index is the indication of the potential for adverse health effect due to chemicals. Any value greater than 1 for a single or group of chemicals depicts hazard.

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Intake is calculated by averaging the intake over the period of exposure. The resulting term is called the chronic average daily dose (CADD) and is used to estimate the hazard quotient from each route by comparison with a safe "reference dose“. If the Intake of the chemical is less than Reference Dose, HQ is less than 1.

Hazard Index (HI) is the sum of hazard quotient of each chemical spread over all possible exposure pathways. HI > 1 = Indication of health hazard

Carcinogenic Risk is the product of Lifetime Average Daily Dose (LADD) and Toxicity Factor. Carcinogenic Risk is calculated for lifetime avg of 70 years.

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Risk Modeling Concept

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Risk Modeling Concept(ingestion of groundwater)

Equations presented in EPA's Risk Assessment GuidanceCalculation of Intake (Dose) expressed in mg/day of chemical taken into the body per unit body weight [mg/kg-d]

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Risk Modeling Concept(inhalation of air)

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Risk Modeling Concept

For Non-carcinogenic risk

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Risk Modeling Concept

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Risk Modeling Procedure

The HHRA software involves 5 steps

Step 1: Choose Chemicals of ConcernRISC5 software contains directory of 128 chemicals (both carcinogens and non-carcinogens). Chemicals of Potential Concern (COPC) are chosen from this database. (The user must have adequate knowledge of the chemical and toxic properties of the chemical, which are to be considered as COPC)

Step 2: Define Conceptual Site Model (CSM)CSM are used to describe the location of the contaminated media, potential transport pathways, location of exposure points and types of receptor points and exposure pathways that could occur.

Step 3 : Determine Receptor Point ConcentrationsUse the receptor point (source) concentrations (in mg/m3 or mg/l or mg/kg) for the various exposure media, namely, ambient air (indoor and outdoor), surface water, groundwater and soil.

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Risk Modeling Procedure

Step 4 : Describe the ReceptorsThe receptors of concern are chosen and the receptor specific intake parameters are entered. The RISC5 software contains default type exposure parameters for many different types of receptors.

The exposure routes / pathways are selected for each media, exposure parameters (one or two receptors, conservative or typical exposure) are entered and chemical specific parameters are entered.

EPA considers the conservative exposure as upper percentile exposure defaults and typical exposure as the mean or average percentile. In additive cases, the exposure for the two receptors are evaluated and then summed.

Step 5 : Start Simulation View and Save Results

Exposure Pathways for each Receptor Media

Media Receptor Potential Exposure PathwaysOutdoor AirIndoor Air

Adult Resident-RMEAdult Resident-TypicalChild Resident-RMEChild Resident-Typical

Inhalation

Groundwater & Surface Water

Adult Resident-RMEAdult Resident-TypicalChild-Resident-RMEChild Resident-Typical

Ingestion Dermal Contact during bathing Ingestion of vegetables grown

using the contaminated water

Soil Adult Resident-RMEAdult Resident-TypicalChild Resident-RMEChild Resident-Typical

Ingestion Dermal Contact with Soil Ingestion of vegetables grown

on the contaminated soil

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Exposure Concentrations used in Software for Calculating Risk (Sample)

Media Unit Conc. RangeArithmetic Mean /50th percentile

Reasonable Maximum Exposure (Upper Percentile)

Ground Water        Lead as Pb mg/l 0.01 - 0.03 0.023 0.03Nickel as Ni mg/l 0.011 - 0.022 0.016 0.022Arsenic as As mg/l 0.002 - 0.004 0.003 0.004Soil        Arsenic as As mg/kg 0.05 – 0.56 0.263 0.56Mercury as Hg mg/kg 0.04 – 0.21 0.144 0.21Nickel as Ni mg/kg 5.8 - 16.8 13.34 16.8Lead as Pb mg/kg 4.2 - 10.5 7.91 10.5Air (Outdoor)        Benzene mg/m3 0.00032 - 0.00046 0.0004 0.00046Benzo(a)PyreneBaP

mg/m30.00000005 -0.00000025

0.000000172 0.00000025

Arsenic (As) mg/m30.00000011 -0.00000022

0.000000157 0.00000022

Mercury(Hg) mg/m30.00000006 -0.00000018

0.000000128 0.00000018

Nickel (Ni) mg/m30.0000005 -0.0000019

0.00000126 0.0000019

Lead (Pb) mg/m3 0.00015 -0.00034 0.000223 0.0003416 emtrc

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Summary of Hazard QuotientChemical

Inhalation of Indoor Air

TOTAL

Arsenic 2.6E-02 2.6E-02Benzene 1.3E-02 1.3E-02Benzo(a)pyrene ND NDLead ND NDMercury (inorganic) ND NDNickel (soluble salts) 1.7E-02 1.7E-02TOTAL 5.5E-02 5.5E-02

Summary of Carcinogenic RiskChemical

Inhalation of Indoor

AirTOTAL

Arsenic 5.7E-07 5.7E-07Benzene 1.0E-06 1.0E-06Benzo(a)pyrene 2.9E-07 2.9E-07Lead ND NDMercury (inorganic) ND NDNickel (soluble salts) 1.4E-07 1.4E-07TOTAL 2.0E-06 2.0E-06

Typical summary sheet from RISC5 software

Summary of Output Files from Software

NON CARCINOGENIC RISK DUE TO INDOOR AIR QUALITY

Category of Risk Adult Population Child Population Acceptable Limit

Maximum Risk 0.049 0.049 1

Mean Risk 0.028 0.030 1

CARCINOGENIC RISK DUE TO INDOOR AIR QUALITY

Category of Risk Adult Population Child Population Acceptable Limit

Maximum Risk 0.0000013 0.0000015 0.0001

Mean Risk 0.00000029 0.00000044 0.0001

NON CARCINOGENIC RISK DUE TO OUTDOOR AIR QUALITY

Category of Risk Adult Population Child Population Acceptable Limit

Maximum Risk 0.0051 0.049 1

Mean Risk 0.00019 0.001 1

CARCINOGENIC RISK DUE TO OUTDOOR AIR QUALITY

Category of Risk Adult Population Child Population Acceptable Limit

Maximum Risk 0.00000035 0.0000029 0.0001

Mean Risk 0.00000000529 0.000000058 0.0001

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NON CARCINOGENIC RISK DUE TO GROUNDWATER QUALITY

Category of Risk Adult Population Child Population Acceptable Limit

Maximum Risk 0.63 0.93 1

Mean Risk 0.32 0.76 1

CARCINOGENIC RISK DUE TO GROUNDWATER QUALITY

Category of Risk Adult Population Child Population Acceptable Limit

Maximum Risk 0.000058 0.000052 0.0001

Mean Risk 0.000011 0.000017 0.0001

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Summary of Output Files from Software

NON CARCINOGENIC RISK DUE TO SOIL QUALITY

Category of Risk Adult Population Child Population Acceptable Limit

Maximum Risk 0.024 0.11 1

Mean Risk 0.0039 0.012 1

CARCINOGENIC RISK DUE TO SOIL QUALITY

Category of Risk Adult Population Child Population Acceptable Limit

Maximum Risk 0.0000021 0.0000019 0.0001

Mean Risk 0.00000012 0.0000000019 0.0001

Sample demographic survey

o Unsatisfactory living conditions. Inadequate ventilation in house resulting

in exposure to high indoor air pollution.

o Almost 90% use cow dung and wood as domestic fuel

o Almost 50% population practice open defecation

o !00% population of village located in upwind direction consume home

grown food and vegetables. People of villages located in downwind

direction consumes outside food and vegetables.

o Food habits are almost similar in all the villages. Rice + vegetables is the

staple food for almost all of the population for breakfast, lunch and dinner.

Arhar dal is used once a week by 80% people. Moog dal is used by only

10% of the population once a week. No other pulses are used.

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o Milk and fruits are consumed by only 10% of the population

o About 80% people are non-veg. 90% of then consume chicken / meat once

a month. Egg is used once a week.

o 75% people keep domesticated animals like cow, buffalo, goat, hen, etc in

the houses.

o People of village located in upwind direction complained of only chest

pain. People of villages located in downwind direction complained of

breathing problems, shortness of breath, coal, cough, besides chest pain.

o Only 3% people of village located in upwind direction spent >5000/- per

year on medicine. About 10% people of village located in downwind

direction reported to spend >5000/- per year on medicine.21 emtrc

Sample demographic survey

Sample health study (1)

Infants: 0-1 year• Cough was the usual complaint. Vitals were within normal limits and so was the respiratory rate.• Hairs were normal and fontanel closure was on time with no abnormality like bulging of the fontanel was observed. • Examination of eyes, ears, tongue as well as mouth also did not reveal any abnormality.• Examination of neck did not show any abnormality but one case did have scoliosis. • Abdominal examination, genital examination and systemic examination did not show any abnormality. • Apex beat in all the cases was centrally placed and shape of the chest was normal in all the cases screened. Prevalence of diseases / complaints were more in villages located in downwind direction. Prevalence of diseases / complaints is negligible in village located in upwind direction22 emtrc

Children (1-5 years)• Recurrent infection and hospitalization in 10%• Cough and expectoration prevalent• 10 % male children and 13 per cent female children had increased respiratory and heart rates. • The examination of fontanel also did not show any abnormality. • The eye examination was also normal with occasional cases showing muddy conjunctiva. • Almost half the children had poor dental hygiene and bad teeth. Some had dental caries.• Tongue examination did not show any abnormality• Abdominal examination, examination of genitalia did not show any abnormality. • Trachea, apex beat were centrally located in all the subjects screened and systemic examination did not reveal any abnormality. Shape of the chest was normal. • Prevalence of diseases / complaints were more in villages located in downwind direction. Prevalence of diseases / complaints is negligible in village located in upwind direction23 emtrc

Sample health study

Children: 5-15 year • All male children were healthy looking but one female had cyanosis and four were febrile.  • Hairs were of normal texture in most cases but in nearly 25% cases pediculosis was observed. • The fontanels showed no abnormality. • On eye examination one case of xerosis was observed. •  Dental hygiene was poor in many cases with caries and mottling of teeth present is some cases. • The tongue examination was normal. • Ear examination did not reveal any disease condition • Systemic examination was normal in all cases. • Prevalence of diseases / complaints were more in villages located in downwind direction. Prevalence of diseases / complaints is negligible in village located in upwind direction

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Sample health study

Adults• There were no cases of obesity though few cases of low BMI. • Few cases of COPD were detected, mostly in males-smokers• Cough, breathlessness, wheeze, and chest pain were the main complaints.• Occasional cases of corneal clouding, muddy and pale conjunctiva was observed -more in cases of females. • Ear and tongue examination were normal. • Some complained of having bleeding gums. Surprisingly, no caries was observed.• Prevalence of diseases / complaints were more in villages located in downwind direction. Prevalence of diseases / complaints is negligible in village located in upwind direction

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Sample health study

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Hospitalization of Infants and children are found more common for the treatment of cough, cold, pneumonia, rhinitis and Diarrhea. 27.42% of study group of <5 children had problem of cough, 24.19% had rhinitis, 13% had problem of breathlessness, 9.68% had wheeze.

64.29% of study group of >5 children had problem of cough, 42.86% had expectoration, 39.29% had problem of breathlessness.35.71% had rhinitis, 17.86% had wheeze and dyspnoea.

65% Infants had normal respiratory rate while 20% had low respiratory rate and 15% had increased respiratory rate.

Maximum elderly people had complain of coughing (51.66%), breathlessness (45%), headache (41.66%), expectoration (40%), anorexia (35%), chest pain (30%), Dysnoea (28.33%), Rhinitis (25%), Fever (23.33%), Wheeze (13.33%), Black colour sputum (11.66%), Haemoptysis in 8.33%.

Sample health study (2)

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Findings of HHRA study (Sample)

Existing environmental quality do not pose concern for carcinogenic risk because the modeled results are below the acceptable risk of 0.0001.

Existing environmental quality do not pose any health hazard because the Hazard Index is < 1.

Health screening did not reveal any serious health risk in the population.

Major health issues in the area are related to public health, which are availability, affordability and accessibility of clean drinking water.

The sanitation and cleanliness as well as disposal of night soil due to open defecation appear to create the most serious health problem.

Another issue that could have profound health impact particularly on children and infants relate to indoor air pollution created by use of domestic wood and cow dung burning in poor ventilated kitchen.

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