HEAVY METAL ASSESSMENT

1
HEAVY METAL ASSESSMENT AT LATVIAS EMEP STATIONS
Lyulko, I. and Frolova, M.
Observation Network Department, Latvian
Environment, Geology and Meteorology Agency,
165, Maskavas Str., Riga LV1019, Latvia fax
371 7145154 e-mail epoc_at_meteo.lv
2

• History of heavy metal measurements

early heavy metal (Pb, Cd, Cu and Zn)
measurements cover surface and the Baltic Sea
waters
1974
Pb, Cd, Cu and Zn monitoring in the ambient air
of major towns
1986
Pb, Cd, Cu and Zn measurements in precipitation
at local stations
1994
observations at the stations of Rucava and Zoseni
under the EMEP programme
1993/94
air sampling of a weekly exposure at the stations
of Rucava and Zoseni
1995
precipitation sampling of a weekly exposure at
the stations of Rucava and Zoseni
2003
extended measurement programme to cover As, Ni
and Mn
2001/2003
3

• History of heavy metal measurements

Air and precipitation heavy metal measurement
programmes at EMEP stations

• Rucava

4

• History of heavy metal measurements

Air and precipitation heavy metal measurement
programmes at EMEP stations

• Zoseni

5

• Description of the EMEP monitoring sites

The Latvias EMEP stations provide for the
assessment of ambient air and precipitation
quality at sites under different
physico-geographical conditions
6

• Description of the EMEP monitoring sites

The Rucava station is located in the
south-western part of Latvia, some 10 km east
from the Baltic Sea and 50 km south from the town
of Liepaja with a population of 95000. The
elevation of the station is 18 m BS
The Zoseni station is situated in the
north-eastern part, some 30 km south-east from
the town of Cesis (20000 inhabitants).
The elevation of the station is 182 m BS
7

• Description of the EMEP monitoring sites

Air sampling for heavy metals is made with a
1-stage filterholder with Whatman filter of a
diameter of 47 mm. The total air volume is 20-24
m3 per week.
Home-made BULK samplers for precipitation
collection are placed by the official
meteorological gauge on the meteorological
plot. The open part of the funnel is 1.8 m
above the ground.
8

• QA/QC activities

In 2004, the Latvian Environment, Geology and
Meteorology Agency received an ISO 90012000
(Quality Management Systems-Requirements)
certificate
refinement of standard operating procedures (SOP)
for sampling of heavy metal in air and
precipitation
implementation of NILU Air Sampler System at
Rucava replacement of old filterholders by
the NILU filterholders
commencement of field blank analysis for air (
3 field blank per month), precipitation ( 1
field blank per month) and filters blank
controls
since 2001 heavy metal measurements have been
made at the Environmental Laboratory, with new AA
Spectrophotometers VARIAN SpectrAA 800, VARIAN
SpectrAA 800Z
regular laboratory intercomparisons
9

• QA/QC activities

The data quality control system implemented over
the last years includes
visual inspection of raw data for revealing
erroneous data and misprinting errors
inspection of outliers the detected
concentration over the annual average 4
standard deviation criteria calculated for the 3
previous years, identification of causes of high
concentrations ( unless the cause of high
concentration has been revealed and the
concentration is 1.5 times in excess of the
annual average 4 standard deviation criteria,
flagging of data is implemented using CCC flags
(category Invalid)
10

• Intercomparison results

Unfortunately, the quality of the laboratory
heavy metal measurements based on the
intercomparison results can be evaluated only for
the recent 3 years
During the last 3 years, the heavy metal
determination quality has been improving
However, the results show that the determination
of low heavy metal concentrations, especially of
Pb, As, Ni and Cr, still remains a challenge
11

• Heavy metals in air

Annual average concentrations of heavy metals,
measurement detection limits (MDL) and
concentrations below the MDL
Over the recent years, the annual average
concentrations at the EMEP stations have been
within 0.2-03 ng/m3, Pb 3-6 ng/m3, Zn -10-30
ng/m3, and Cu, Ni and As 1 ng/m3, with a bit
higher values at Rucava. Concentrations below the
measurement detection limits ranged between 1 and
9 in number, wit a higher per cent of cases for
Ni and As
12

• Heavy metals in precipitation

Annual average concentrations of heavy metals,
measurement detection limits (MDL) and
concentrations below the MDL
The annual average heavy metal concentrations in
the precipitation have shown stable values over
the recent years, with higher concentrations at
Rucava. This being so, the number of
concentrations below the laboratory detection
limits has greatly increased especially for Zn,
Ni, As and Mn
13
In historical aspect, an analysis of the annual
average heavy metal values shows that the station
at Rucava has been reporting considerable
fluctuations in the concentrations from year to
year, for instance the great reduction in the
annual mean Cd and Pb values of 1998-1999 was
followed by considerable increases in Cd
(2000-2001) and Pb (2000)
Annual average concentrations of Cd and Pb in the
air (ng/m3) of the EMEP stations, 1995-2004
A more stable, without abrupt year-to-year
fluctuations, reduction in the heavy metal
concentrations has been observed at the station
at Zoseni over the whole measurement period
14

• Heavy metals in air

The 1998-1999 concentrations of Cd and Pb in the
ambient air of Rucava were the lowest for the
whole period of the measurements for Cd, 55 of
the samples in 1998 and 22 in 1999 were below
the measurement detection limits. Unfortunately,
we have not identified the reason for such low Pb
and Cd concentrations. Cd at the station Rucava
showed highest annual average concentrations in
2000 and 2001 and Pb in 2000.
Cd concentrations in air (ng/m3) at Rucava,
1995-2004
15

• Heavy metals in air

In the period 20.04.2000 25.05.2000, the
concentrations of Pb and Cd rose to 70 ng/m3 and
1.83ng/m3, respectively. The sector of air
transport either was not identified or a
northerly wind from the side of Liepaja, that is
50 km to the north of the station, was blowing
during that period. In eliminating those values
from the calculations, the annual average
concentrations in this years still remain maximal
over the whole period under the observation
Pb concentrations in air (ng/m3) at Rucava,
1995-2004
16

• Heavy metals in air

A comparison of heavy metal concentrations
measured with pM10 in the air of Liepaja with the
measured concentrations together with the total
dust at the EMEP station Rucava has shown
differences of 10 to 100 times in the annual mean
concentrations
Pb and Cd concentrations in air (ng/m3) with
pM10 and total dust
17

• Heavy metals in precipitation

The year-to-year variations in the weighted mean
Cd and Pb concentrations in the precipitation are
less pronounced than in the ambient air. This
being so, the variations are wider than in Rucava
Pb
Cu
Annual weighted means (mg/l) of Cd and Pb in the
ptecipitation of the EMEP stations, 1994-2004
18

• Heavy metals in precipitation

The 1999 values for Zoseni were eliminated from
processing as those were an order of magnitude
higher over the whole period
Cd concentrations in precipitation (mg/l) at
Zoseni, 1994-2004
19

• Heavy metals in precipitation

The extreme Pb values for Zoseni in 1995-1997
were eliminated from processing as well
Pb concentrations in precipitation (mg/l) at
Rucava, 1994-2004
20

• National emissions of heavy metals

The Latvias emissions inventories are based on
the EMEP/CORINAIR Inventory Guidebook (3rd
edition)
Total emissions of Pb and Cd (Mg) from Latvian
sources
Pb
Cd
The time-series of the emissions in the last
years have been stable and the emissions have
decreased as compared to 1990. Industries are the
main source of Pb (95) un Cd (66)
Uncertainties and QA/QC activities according to
the Good Practice Guidelines have not been
implemented because of the lack of funding and
human resources. It is a work of the nearest
future
21

• Comparisons modelled and measurement results

Difference () between modelled and measured Pb
deposition
Total lead deposition (mg/m2 per year) in Latvia
The modelled total Pb deposition is much lower
then the measured, with a difference of 63 to 350
during 1995-2001. The modeled Pb deposition at
Rucava station is more underestimated
22

• The trend analysis results

In the period 1995-2002, the decreasing tendency
in the Pb deposition retained, with statistically
significant modeled and measured values at both
stations
The trend analysis results for lead total
deposition, 1995-2002
23

• Conclusions

From the heavy metal analysis it is apparent
that
The heavy metal measurement results for not quite
complete year 1994 (ambient air) and 1993
(precipitation) at the stations Zoseni and Rucava
may be used just as tentative data because the
sampling and analysis methods were tested in
those years, and errors in the measurements were
possible(high values of Cd at Zoseni and low at
Rucava)
The Cd and Pb concentrations in the ambient air
of Rucava in 1998-1999 were the lowest for the
whole period of the observations. The reason for
the decrease in the Cd and Pb concentrations is
unknown
Heavy metal measurements in the various nature
compartments have ascertained a crucial
importance of well-defined and common approaches
to sampling, chemical analysis and data
processing especially in view of the recently
accepted heavy metal directives, 2004/107/EC and
1999/30/EC
24

• Conclusions

From the heavy metal analysis it is apparent
that
It is necessary to refine the heavy metal
measurement standards including sample
preparation and analysis, for PM10 in particular
to make the requirements more precise with
respect to the laboratory determination limits,
the heavy metal determination on the background
level, the quality of field blanks and filter
blanks and the data critical control methods
More close contacts with CCC and cooperation
among the participant countries is necessary in
terms of heavy metal measurement quality. In case
of bad intercomparison results, working meetings
of laboratory specialists should be held for
discussing the issue and activities to be taken
to improve the situation
Annual heavy metal data checking on the Internet
will allow mistakes in data delivery to CCC to be
revealed