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A randomised controlled trial to assess the uptake and effectiveness of a novel filtration system to reduce Arsenic exposure in rural West Bengal

Ghislaine Rosa Environmental Health Group

Department of Disease ControlLondon School of Hygiene and Tropical Medicine University of London

Background: Extent of the problem

• Contamination of groundwater by geogenic arsenic (As) has been highlighted as an environmental disaster, known as the “largest poisoning of a population in history”

• Over 60 million people are affected worldwide

Although national and international aid agencies and local governments have been working on this issue, the success has been limited and the problem prevails

Background: Health impact

• Chronic exposure of Arsenic through drinking water leads to

- Skin lesions- Skin cancer- Internal cancers (kidney, liver, and lung)- Cardiovascular disease- Other adverse effects

• Increasing evidence of negative effects of exposure to arsenic in drinking water on foetal growth, foetal loss, and infant mortality, as well as neurodevelopment in school-age children

Pilot study: Aims and objectives

Research aim:Explore the potential for the Unilever Pureit As+ filter to reduce arsenic exposure among a population currently using drinking water sources with moderate to high exposure to arsenic via groundwater.

Pilot study: Aims and objectives

Specific objectives:

1.Assess the effectiveness of the Pureit As+ filter in decreasing the body burden of arsenic (total urinary arsenic)

2.Assess arsenic removal performance in drinking water of the Pureit As+ filter y in the field

3.Examine the microbiological performance of the Pureit As+ filter in the field

4.Examine uptake, consistent use, and acceptability of the Pureit As+ filter

Study site

• Study was conducted in North 24-Parganas district- One of the nine districts with an Arsenic problem

• Conducted in (Gaighata block)• Conducted in two adjacent villages• - Goshpara• - Bhadradanga• All public water sources tested

positive for Arsenic contamination (As>50μg/L)

Study site

• Study was conducted in North 24-Parganas district- One of the nine districts with Arsenic contamination in ground waters

• Conducted in (Gaighata block)• Conducted in two adjacent villages

- Goshpara- Bhadradanga

• All public water sources tested positive for Arsenic contamination (As>50μg/L)

• Sub-sample of private sources tested positive for Arsenic

Study design

• Chemical and microbiological performance was assessed using a parallel, household-randomised controlled trial (RCT) design over a four-month follow-up period

• An open (non-blinded) design was used due to complexity to blind filtration systems

• Randomisation undertaken by public lottery

• Monthly follow-up visits (4 rounds) collecting data on usage and health as well as collecting samples of drinking water and urine from female head of household for analysis

• Qualitative study undertaken at the end of the follow-up period

• RCT is registered at Clinicaltrials.gov.

The intervention: Pure it As+ (Unilever Ltd).

• Based on the already marketed Pureit Classic filter

• Extra component to remove arsenic (Polisher)

• Microbiological and arsenic removal based on multi-barrier mechanism:– Mesh– Activated carbon trap– GermKill processor– Polisher

• Live time: 2000L

• Storage capacity: 9L

Flow chart of study participants

Baseline (Assessed for eligibility) (n=432)

Excluded (n= 136 )  Not meeting inclusion criteria (n= 104, 24.1%)  Declined to participate (n= 59, 13.7%) Not eligible (n=32, 6.3%)

Allocated to intervention (n=136) Allocated to control (n=133)

Randomised (n=269)

AllocationFebruary 2015

Follow-Up 1March 2015

Enrollment February 2015

Follow-Up 2April-May 2015

Follow-Up 4July 2015

Follow-Up 3June 2015

Qualitative study

July 2015

Results: BaselineGood balance between arms was achieved in socio-demographic characteristics

Results: Baseline resultsGood balance between arms was achieved in WASH characteristics

Results: Baseline arsenic levels in drinking waterGood balance between arms was achieved

Results: Usage

• On average, across the 4 follow-up visits:- 98.7% of filters looked in use- 92.4% of filters had water- 81.2% of intervention households reported drinking filtered water- 65.8% of intervention households were drinking directly from the filter, the

drank from a narrow-neck container

• 94.0% of intervention households with school-aged children reported that their children took filtered water to school

• Of the 47.4% of HOH that took water to their work, 97.6% took filtered water

Results: Exclusive drinking of treated water

AdultsOn average, across the 4 FU visits, 40.1% of respondents reported consuming untreated water in last 24 hours.

ChildrenOn average, across the 4 FU visits, 25.3% of respondents reported consuming untreated water in last 24 hours.

Exclusive use of the filter during follow-up was suboptimal:

Number of visits reporting to have consumed untreated water in previous 24 h

Adults <5s

0 24.6% 50.0%1 25.4% 35.0%2 24.6% 20.0%3 18.3% 5.0%4 7.1% 0.0%

Preliminary results: Urinary arsenic

A median reduction of 46.0% was achieved in FU1 (p<0.001) , and a reduction of 40.5% in FU2 (p=0.005)(based on 1/3 of samples).

NOTE: Still awaiting results from follow-ups 3 & 4.

Preliminary results: Arsenic content in drinking water

• Unfortunately we have still awaiting for these results

Preliminary results: Microbiological performance

Preliminary results: Microbiological performance

Preliminary results: Microbiological performance

Conclusions

• High uptake of the Unilever As+ filter was observed, but use was not exclusive.

• The filter improved the microbiological quality of the drinking water but this was compromised when stored on a separate container.

• A significant reduction in urinary Arsenic among the female heads of the household was observed 1 month after delivery of the filter.

• Analysis of the qualitative component of this study will improve our understanding of the drivers and barriers to the consistent and exclusive use of the filter.

Acknowledgements

Dr. Subhamoy Bhowmick & Prof. Debashis Chatterjee, Dept. of Chemistry, Kalyani University & all staff at GSFS

Thank you!

Questions???