This report, representing the fourth in a series on a biological monitoring programme, describes the nematodes found in the mineral soil of 18 dairy-cattle farms located on grasslands with peat soils. These nematodes are also compared with the nematodes found on earlier sampled dairy-cattle farms on sandy soils. The farms had different numbers of cattle (mainly cows) per ha, leading to differences in the amounts of manure per ha which were supposed to be indicated by the concentrations of phosphate. The average number of nematodes found (9400 per 100 g soil ) comes very close to the number found on the extensive cattle farms on the sandy soils (10,000 per 100 g soil). The numbers of nematodes found in the intensive farms on sandy soils are higher (12,400 per 100 g soil), while those of the most intensive farms (6600 per 100 g soil) are lower. Increases in cattle intensity lead, on average, to the different farm types showing higher numbers of bacterivores and lower numbers of plantfeeders. The different indices, trophic diversity index T, maturity indices MI and Sigma MI, Shannon-Weaver index H', index of richness SR and the index of 'evenness' J', as well as the number of taxa N, are highest in the peat and sandy soils of the extensive farms, while lowest in the intensive farms. The number of nematodes from c-p group 1 (colonizers) increases with higher manure production.

This study compiles environmental concentrations of pesticides. Pesticide concentrations in surface water, groundwater, the atmosphere, soil and sediment are presented. The compilation is limited to measurements in the Netherlands. Information on these concentrations could be found for less than half of the 270 active ingredients, that are registered in the Netherlands. The current investigation shows that compounds in water quite often exceed the maximum accepted level for water (0.1 mug/l) used as source for drinking water. Some substances have been analysed, but they never exceeded the detection limits. Many substances have not been analysed at all. It was found that all but two compounds detected in groundwater exceeded this environmental quality objective.

In September 1998 the Dutch National Institute of Public Health and the Environment (RIVM) published the fourth National Environmental Balance (MB98) in Dutch. Here, the environmental quality resulting (partly) from the environmental policy at the time is quantified for the period 1985-1997. Supplemental to this fourth Environmental Balance is an outlook for the period 1997-2002. This report serves as a background document for the section on transport in the MB98. Major conclusions drawn from this outlook are: (1) the increase in the use of most transport modes in 1997 compared to 1996 and the prediction that in 2000 the use of passenger cars will be approximately 5% higher than the SVV-II policy target; (2) the increase in CO2 emissions by road traffic up to at least 2002, mainly because short-term improvements in energy efficiency of passenger cars are not expected; (3) the decrease in other emissions (aerosols, CO, VOC, NOx and SO2) as a result of the successful penetration of the three-way catalytic convertor in the passenger car and light-duty vehicle stocks, as well as a further decrease forecasted for the emissions up to 2002, except for SO2; (4) the approximate 7% increase in CO2 emissions from the use of Dutch bunker fuels by international sea and air transport in 1997 compared to 1996. CO2 emissions from these bunker fuels amount to more than twice the CO2 emissions from passenger cars on Dutch territory.

This report presents tabulated National Air Quality Monitoring Network results for the regions Limburg, Noord-Brabant and Zeeland for the calendar year 1994, summer 1994, winter 1993-1994 and 1 April 1993 - 31 March 1994 (tropical year: EC reference period). The components monitored were: fine dust (PM10), CO, Ox (=NO2+O3), O3, NO2, NO, NOx (=NO2+NO), black smoke (= suspended matter measured by the black-smoke method) and SO2. The fine dust (PM10) measurements were corrected for a systematic underestimation caused by the sampler. In a check made at all stations in the network for exceedance of Dutch limit values in 1994, exceedances for black smoke, PM10 and O3 were observed. The limit values for SO2, NO2 and CO were not exceeded.<br>

This report is based on reports from provinces and municipalities on exceedances of the air quality standards for the compounds sulphur dioxide, suspended particles (black smoke), nitrogen dioxide, carbon monoxide, lead and benzene. No exceedances of air quality standards were reported for industrial areas. For 116 roadblocks exceedances were reported: 52 times benzene, 62 times nitrogen dioxide and 2 times carbon monoxide

This report presents the tabulated results of the regional stations of the National Air Quality Monitoring Network in the regions 4 (Zuid-Holland) and 5 (Noord-Holland) for the calendar year 1998, summer 1998, winter 1997-1998 and 1 April 1997 - 31 March 1998 (tropical year: EU reference period). The components measured were: NH3, fine dust (PM10), CO, oxidant (Ox , which is NO2+O3), O3, NO2, NO, NOx (=NO2+NO), black smoke (which is suspended matter measured by the black smoke method) and SO2. The fine dust (PM10) measurement data are multiplied by a factor 1.33 to correct the systematic underestimation when compared to the EU reference method for PM10.<br>

In recent years an increase of severe invasive infections and toxic shock syndrome (TSS) with beta-haemolytic Group A streptococci (Streptococcus pyogenes, GAS) has been reported from North-America and North-Western Europe. In the spring of 1992 several reports of cases suggested that this epidemic wave might have reached the Netherlands. Subsequently a national surveillance was initiated. Between 1-7-1992 and 31-12-1993 GAS-isolates from 440 patients were sent to the public health laboratory for typing ; from 220 of those 440 patients (50%) demographic and clinical data were obtained. In 132 of those 220 patients invasive infection with GAS was clinically and bacteriologically documented. Forty-one of those 132 patients (31%) suffered from TSS. Cases were not associated with a particular geographical region. The incidence of TSS was highest in the age groups of 30 to 50 years and in individuals older than 60 years. Mortality associated with TSS was 51%. In the majority of cases (61%) no underlying diseases were reported. In 20 of the 41 TSS-cases no obvious portal of entry for infection was detected. In the remaining cases diverse primary local infections were observed. In 30% of cases fascitis necroticans and/or myositis was present. In 11% of cases TSS was acquired in the hospital. Type T1/M1 was the etiological agent in 31% of all (440) patients ; none of the other 19 different T/M- types found contributed more than 10%. T1/M1 was strongly associated with TSS (22 of 41 cases, 54%). Ninety-two percent of the T1/M1 strains contained the bacteriophagelocated gene for exotoxine A. RFLP analysis of the M1 gene of T1/M1 strains revealed one single pattern.<br>

In 1995 and 1996, radon concentrations and effective air flows were measured in about 1500 Dutch dwellings built between 1985 and 1993. The goal of this investigation was to describe the trend in the average radon concentration and quantify the relative importance of the different sources of radon. In the living room radon concentrations varied from 5 to 400 Bq/m3, with an average of 30 Bq/m3, which is 50% higher than the average measured in 1984 in dwellings built before 1970. The average concentration in the outside air was 5 Bq/m3 and in crawl spaces 70 Bq/m3. The average concentration found in bedrooms was about 10% less than concentrations for living rooms. Measurements of effective air flows showed the most important source of radon in the living room not to be the soil but the building materials, with an average contribution of 70%. The other 30% comprised outside air and air from the crawl space in equal quantities. Use of the mechanical ventilation system was found to slightly reduce the radon concentration in new dwellings. The radon concentration was also found to be positively correlated with the radon concentration in the crawl spaces and the total area of concrete in the living room. The long-term increase in the average radon concentration is due principally to the improvements in insulation since 1970, resulting in a fourfold decrease in the building shell permeability, and in a less degree to an increase in the use of concrete by a factor of four over the last 40 years. Since 1970, the average radon concentration in the total Dutch housing stock has increased by about 4 Bq/m3, to 23 Bq/m3, which is the lowest but one average value in Western Europe.

The objective was to obtain insight into the current incidence of pertussis. Design: Comparison study from different surveillance sources. Method: For the years 1989-1994 the incidence of pertussis was estimated from the number of pertussis notifications, from laboratory data from serodiagnosis, isolations of Bordetella and from the national registration of clinical diagnosis of hospital admissions. Results: The number of notifications and positive serological results yielded similar average annual incidence for the period 1989-1994 (2.3 and 2.2/100,000, respectively). According to notifications peak incidences occurred in 1989 (3.5/100,000) and 1994 (3.4/100,000). For positive serodiagnosis the incidences in 1989 and 1994 were 2.4/100,000 and 3.2/100,0000, respectively. In 1993 the incidence of notifications and positive serodiagnosis (2.4 and 3.2 per 100,000) was also higher than in the other years. The incidence based on hospitalizations, notifications and positive serology was highest among children younger than one year. In 1994 and 1993 the estimations for the vaccine efficacy were 84% (95%-confidence interval 80-87%) and 92% (95%-confidence interval 90-94%), respectively. Conclusion: For 1989-1994, the pattern indicated that pertussis is endemic with four-yearly peaks. The incidence of hospitalizations emphasizes the seriousness of the illness in infants. Due to the vaccine coverage in the Netherlands, the incidence among unvaccinated children is much lower then among unvaccinated children in neighbouring areas with lower vaccine coverage. It is important that general practitioners are aware of the occurrence of pertussis in vaccinated and unvaccinated children and adults. The probable decrease in vaccine efficacy (92% in 1993; 84% in 1994) needs special attention and must be monitored. This stresses the importance of continued surveillance.<br>

Abstract not available