Excess risk of kidney disease mortality in a population living
near industrial processes
Susan Hodgson (MSc)1, Mark J Nieuwenhuijsen (PhD)2, Anna Hansell (Dr)1,
Sasha Shepperd (D.Phil)1, Tracy Flute (BSc)3, Brian Staples (Dr)4,
Paul Elliott (Prof)1, Lars Jarup (PhD)1
1Small Area
2Dept
Environmental Science and Technology, Imperial College London, UK.
3Warrington
4Cheshire
Trust
Health Statistics Unit (SAHSU), Imperial College London, UK.
Primary Care Trust & Halton Primary Care Trust
and Merseyside Health Protection Team, Central Liverpool Primary Care
Introduction
‘Runcorn is exposed to the irritating vapours cast off so freely by the large
chemical works in its vicinity’ Medical Officer of Health for Runcorn, Lancet,
January 1880.
Runcorn is still polluted by local industry, with substantial amounts of
nephrotoxic chemicals (including lead, mercury, arsenic, chromium and
solvents) being released annually.
We undertook preliminary investigations into the health of the population
living in the vicinity of industrial processes.
The aim of this study was to determine if there was an excess risk of kidney
mortality and morbidity in people living near the industrial processes.
Methods – mortality analysis
Mortality was investigated using routinely collected data supplied by the
Office for National Statistics (ONS).
Analysis was carried out using the SAHSU Rapid Inquiry Facility (RIF).
Standardised Mortality Ratios (SMR) adjusted for socio-economic
deprivation were calculated for deaths from nephritis, nephrotic syndrome
and nephrosis (ICD9 580-589) over the years 1981-1999.
Distance from industrial processes was used as a proxy for exposure populations living within 0-2km and between 2.01-7.5km of 16 installations
were investigated.
Expected figures were derived from the North West region population.
Methods – morbidity analysis
Morbidity was assessed by the former North Cheshire Health Authority
(NCHA).
Kidney disease was mapped at electoral ward level using routinely
collected local hospital admissions data (1990 to 1999).
District age Standardised Admission Ratios (SAR) were calculated for
non-malignant renal disease as well as kidney cancer (ICD9 580-583
(except 581.8, 582.8 and 583.8), 585-587, 189.0; ICD10 N00-N06, N10,
N11.8, N11.9, N15.8, N18, N19, N26, C64).
The population of Warrington and Halton was used as the reference.
Results
Mortality study using RIF
Distance
Sex
Unadjusted for deprivation
0-2 km
Male
Female
2.01-7.5 km
Male
Female
Adjusted for deprivation
0-2 km
Male
Female
2.01-7.5 km
Male
Female
Obs
Exp
SMR
95% CI
32
47
166
206
23.87
29.3
152.03
182.47
134
160
109
113
92 - 189
118 – 213
94 - 127
98 – 129
32
47
166
206
24.41
29.18
154.41
185.92
131
161
108
111
90 - 185
118 - 214
92 - 125
97 – 127
Morbidity
Town
Sex
SAR
95% CI
Runcorn
Male
122
110-136
Female
136
122-151
Male
91
85-97
Female
84
78-91
Warrington
Discussion
•Significant excess of kidney mortality in people living nearest polluting
sources
•Significant excess kidney morbidity in areas closest to the polluting sources
•Consistent pattern using two different methods and independent data sources
•Unlikely to be explained by occupation
Further work is being being carried out to establish if the excess
risks are causally related to chemical pollution in the area.
Ongoing work
Exposure Assessment
Air dispersion modelling of mercury and lead using ADMS-Urban (version 1.6)
developed by CERC.
This model will not provide a quantitative estimate of past exposures, but should
indicate the extent of dispersion of mercury and lead, and highlight areas where
exposure is significantly higher than the background levels experienced elsewhere
in the UK
Modelled versus measured ambient mercury and lead levels, 2000
Modelled vs measured mercury levels at Weston County
Primary School
0.08
0.07
Measured results
Modelled results
Hg (ug/m3)
0.06
Ave measured value
0.022 g Hg/m3
0.05
0.04
0.03
Ave modelled value
0.02
0.01
0.028 g Hg/m3
29
-F
eb
07 -00
-M
a
14 r-00
-M
a
21 r-00
-M
a
28 r-0
-M 0
a
04 r-00
-A
pr
11 -00
-A
pr
18 -00
-A
pr
25 -00
-A
pr
02 -00
-M
a
09 y -0
-M 0
a
16 y -0
-M 0
a
23 y -0
-M 0
a
30 y -0
-M 0
ay
06 -0 0
-J
un
13 -0 0
-J
un
20 -0 0
-J
un
27 -0 0
-J
un
-0
0
0
Modelled vs measured lead levels at Elton Community
Centre
0.04
0.035
Measured results
Modelled results
Pb (ug/m3)
0.03
0.025
0.02
0.015
0.01
0.005
0
00
00
00
00
00
00
00
00
00
00
00
00
rrbynnyrrbbna
a
e
a
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p
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-F
-F
-M
-M
-A
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26920
20
15
29
14
28
11
25
23
Ave measured value
0.014 g Pb/m3
Ave modelled value
0.008 g Pb/m3
Model Validation
• Air monitoring will be carried out by the Environment Agency based
on the model output.
• Urine samples will be collected from ~200 individuals. Mercury in
urine will be determined by the HSL, Sheffield, using Inductively
Coupled Plasma – Mass Spectrometry (ICP-MS).
Health outcomes
• Further analysis of routine databases on mortality, cancer incidence
and Hospital Episode Statistics.
• Individual level sub-study will assess the prevalence of early kidney
damage using urinary biomarkers such as N-acetyl-β-glucosaminidase
(NAG) and urinary β2-microglobulin.