5.1. Ranking of Districts
Pooled results of the soil environment risk assessment, residents’ health safety, social conditions, and land use analysis of districts are presented in
Table 3 and in
Figure 2,
Figure 3,
Figure 4,
Figure 5,
Figure 6,
Figure 7,
Figure 8 and
Figure 9, below.
The soil environment risk analysis of districts pointed to the most significant risk for the districts Wola, Ursus, and Praga Południe, with total scores of 1,106,667, 136,850, and 534,146, respectively (
Figure 2). The district with the lowest soil environment risk was Wesoła, with a result of 54,031. In the Wola district, 18 out of 25 analyzed compounds showed exceedance of the acceptable values; the districts Praga Północ, Włochy, and Żoliborz showed 16 cases, with the lowest number of cases being found in the Wesoła district—6. The presented results may carry a high estimation error for several reasons: the small number of measurement points, the high variability in the number of analyzed samples among the districts, the high degree of averaging of results due to the application of arithmetic average for district surface area, and incorrectly adopted point scales. The soil contamination values in districts constitute averaged data, dependent on specific values obtained at sampling points, the number of which, in particular districts, was highly variable. Although the sampling points were distributed in regular grids (4 samples/km
2 for inorganic substances, and 1 sample/km
2 for organic compounds), their number in particular districts varied from 30 to 318 for inorganic substances, and from 8 to 77 for organic compounds. The coefficient of distribution of measurement points in a district for inorganic substances ranged from 0.24 to 0.28, with a standard deviation value of 0.01. The coefficient of distribution of measurement points in a district for organic compounds ranged from 0.92 to 1.06, with a standard deviation value of 0.04. The obtained values of the coefficient of distribution of measurement points should be considered to be characterized by low variability. Despite limitations related to the possibility of the over- or underestimation of the result, due to the presence of at least one considerably deviating data point, the application of the arithmetic average was justified. The primary assumption was to estimate the average soil environment risk of the district, as even point contamination with toxic substances is of importance in such cases. The point scale adopted for the soil environment risk assessment and developed for this publication is based on the knowledge and experience of the renowned Environmental Protection Agency (EPA), which has been studying brownfields for many years. Unfortunately, due to the lack of data with higher accuracy, it was impossible to apply the already-tested calculation algorithms presented by Litt et al. [
10], which are based on EPA data.
In terms of the health safety of residents, the least favorable conditions were determined for the districts Praga Północ, Wola, and Targówek, with total scores of 33, 71, and 79, respectively, and the most favorable conditions for Wilanów, with a total score of 257 (
Figure 3). Praga Północ particularly stands out, where 12 out of 16 of the analyzed indices received the worst results in that district.
The least favorable social conditions occurred in the districts Praga Północ, Wola, and Rembertów, scoring 9, 24, and 43, respectively (
Figure 4). Each of the analyzed indices for the assessment of social conditions, i.e., unemployment, share of the unemployed with the lowest level of education, and level of use of social welfare, showed the Praga Północ district to possess the most unfavorable values. Therefore, the total score for the district achieved the lowest possible result, namely 9, with nine analyzed indices. The Wilanów district achieved the most favorable outcome in the analysis of social conditions, totaling 162 out of a total possible score of 162.
According to the analysis of the change in land use over the decade 2004–2014, the greatest changes in terms of the surface area of industrial objects were observed in the Rembertów district, where the area of industrial land increased by 149 ha, accounting for 7.72% of the district area. The greatest losses of industrial land were recorded in Żoliborz, 4.72%, Wola, 3.32%, and Mokotów, 2.37% (
Figure 5), whereas, in terms of absolute values, the greatest losses occurred in Mokotów, 84 ha, Wola, 64 ha, and Bielany, 49 ha (
Figure 6). The recorded changes did not exceed 2% of the district area in the remaining districts, except for Ursynów, where the share of brownfields remained unchanged. The analysis of land included in RHZPZ permitted the assessment of the dynamics of changes in contaminated areas, due to historical industrial activity, among other things. The highest numbers of areas included in the register can be found in the districts Wola, Mokotów, and Praga Południe, at 54, 26, and 11, respectively (
Figure 7). The greatest percent contribution of land included in the register in the district area was observed in Ursus, Żoliborz, and Wola, at 2.76%, 1.63%, and 1.48%, respectively (
Figure 8). The largest area was occupied by such land in Wola, 28.45 ha, Ursus, 25.86 ha, and Mokotów 20.12 ha (
Figure 9). However, data from RHZPZ are exclusively of a reference character and do not reflect the actual scale of contaminated land in particular districts. As shown by the inspection of the Supreme Audit Office [
48] for the period 2014–2018, three out of eighteen districts declared the absence of historical earth surface contamination in their area and, in at least two districts, this information was false. Three districts subject to the inspection performed the identification in violation of related provisions. Their records were also conducted in an undiligent manner, failing to include, among other things, land with the occurrence, or likely occurrence, of historical earth surface contamination [
48]. The scale of infringements in the preparation of RHZPZ in Warsaw’s districts is blatant and does not allow for a detailed analysis of the hazard. However, the register has been supplemented since the inspection, and it is currently more accurate. Many of the records of contamination still concern areas where remediation has been completed, and data on land requiring such measures are missing. Nonetheless, information included in said register permits a general assessment of the threat, resulting from historical contamination in the territory of Warsaw. Considering the fact that 179 areas containing, or potentially containing, historical earth surface contamination were identified in the city, with a total surface area exceeding 135 ha, and that this value is underestimated, the related risk should be assumed to be high.
Coefficients of correlation of soil environment risk with health indices, social conditions, changes in the surface area of industrial land, area of land included in RHZPZ, and the corresponding test statistic
p values are presented in
Table 4. The result of the analysis of the correlation between change in the surface area of industrial land, the assessment of health safety of residents, and the surface area of land included in RHZPZ is presented in
Table 5. The results were considered statistically significant when the
p value of the test statistic was lower than, or equal to, 5%.
The majority of tested correlations proved to not be statistically significant. Correlations with considerable significance were related to the soil environment risk of districts and indices for land included in RHZPZ. Both the percent share of land from the register in the district area, and the total surface area of the aforementioned land by the district, show a moderate positive correlation with soil environment risk of the district, reaching rho coefficients of 0.44 and 0.49, respectively, whereas, for the first correlation, the significance level was slightly above the conventional 5%. Moreover, the change in the surface area of industrial land in the years 2004–2014 in particular districts, and the total surface area of land from RHZPZ, are moderately negatively correlated, with a significance level slightly above the conventional 5%. The results show that, in districts with a high share of land included in RHZPZ, higher-than-average soil environment risk occurs, and that it is related to the transformation of industrial land. Analysis shows that land use change in post-industrial land is related to greater soil environment risk. This is an alarming conclusion in the case of Warsaw, because a large part of the former industrial land was transformed into residential use [
36]. Lack of statistical correlations between the remaining indices, including the index of the health safety of residents and soil environment risk, may be a result of the consideration of only one environmental factor, namely soil contamination, and the neglect of other factors, such as those related to contamination of waters, atmosphere, or quality of the residential environment, among others. Moreover, as pointed out by Ringuist [
49], the occurrence of the risk factor alone in a place of residence does not have to entail the highest exposure to a given factor. It may also be the cause of the lack of correlation.
In the detailed analysis of particular districts, the results obtained for the Wola district deserve special attention. It is the area with the greatest soil environment risk, with the largest surface area of land from RHZPZ, and which possesses the second-least favorable indices of health safety and social conditions;
Table 6. The present situation in the Wola district is primarily a result of its industrial past. Employment in the industrial sector in Wola was the highest in Warsaw between 1955–1995, reaching a maximum value of 56,839 employed persons in 1975 [
50]. However, the district’s historical data analysis poses several difficulties, because the borders of particular districts have been subject to numerous changes, in 1951, 1957, 1977, 1992, and 2002, among others. Therefore, the index of industrial employees per 1 km
2 is a better reference. According to Misztal [
50], “among the districts, the area of Wola was the most saturated with industry in the years 1955–1985. Until 1989, it concentrated more than 2000 employees of industry per 1 km
2”. The results show that Wola is an example of a district affected by the phenomenon of environmental injustice, and its residents may be exposed to slow violence. Many historical contaminants deposited in the area of today’s Wola district originated from industrial activity and, according to research by Stiber et al. [
51], a correlation exists between historical industrial use and contamination of the environment.
5.2. Lack of Rational Spatial Planning in Warsaw’s Brownfields
Another factor related to the negative effect of historical earth surface contamination causing exposure of inhabitants is the lack of rational spatial planning in contaminated areas.
The spatial planning system in Poland, as defined in the Spatial Planning Act [
52], is hierarchical, taking into account three levels: national, regional, and local. Documents of lower levels should be created based on provisions of higher-level documents. Among the planning documents of particular importance is the local spatial development plan (miejscowy plan zagospodarowania przestrzennego—MPZP), which is the only legal act in the spatial planning system in Poland. This means that there is a need to comply with the provisions of the local plan. In the case of other documents, there is no such necessity. The local plan is one of the primary instruments for introducing and maintaining spatial order in Poland, including order on post-industrial sites. According to the Local Plan Coverage Ranking, 31.4 % of the country’s area was covered by valid spatial development plans in 2020 [
53]. Local plans are essential in cities and their outskirts where dynamic land use structure changes occur. In the case of voivodship cities in Poland, the coverage of local plans varies from 68% in Kraków to less than 16 % in Rzeszów [
53]. In Warsaw, Poland’s largest city, the proportion of the area covered by binding local plans is 39.57% [
53]. Bartoszczuk [
54] points out that, at the end of 2010, the cover of particular districts of Warsaw with local plans was relatively low—in 14 out of 18 districts, it did not exceed 40% of their area. According to Bartoszczuk [
54], approximately 37% of the area of the Wola district was covered by local development plans in 2010 and, according to data disclosed by the Warsaw City Council [
55], the current situation remains unchanged. In the case of a post-industrial district, this situation can potentially negatively impact the health safety of residents. The local development plan constitutes the basic and exclusive planning document. A land devoid of such a plan can be subject to any transformations at investors’ discretion.
Due to their attractive location and lower prices, former industrial areas are an area of intense interest for investors. A prime example is the Wola district, which is adjacent to the downtown center. Investment pressure in this area is high, and the availability of free land is limited. All land that is not included in the local plan can be freely developed, which creates favorable conditions for investment. By law, the developer is not obliged to carry out a land survey, even if the development is in an area of former industrial plants and the planning designation is residential development. Instead, the developer is obliged to carry out remediation if ground contamination is confirmed. In this respect, the importance of historical land contamination registers is growing because, if they contain accurate information, many risks could be avoided. Unfortunately, the data available in the register for the Warsaw area are of poor quality and do not constitute a sufficient tool to protect the population’s health safety. In the area of the Wola district, as a result of free transformations, numerous examples of the “discovery” of historical earth surface contamination occur at the stage of construction of new residential estates, among others in Obozowa 20 Str. or Skierniewicka 21 Str. [
56]. The examples of the “discovery” of historical earth surface contamination constitute evidence of the lack of rational planning and the failure to provide equal opportunities in terms of distance to a safe residential environment for residents of Wola. In the process of land use change, areas containing historical earth surface contamination are transformed into land for the permanent residences of people, including residential estates—as in the two above-mentioned examples. As a result of repeated serious anomalies during the planning process, Wola residents initiated a bottom–up initiative to identify areas potentially contaminated due to historical industrial activity [
57]. Residents developed a map of post-industrial areas with potential land contamination on their accounts. The study is not a professionally prepared document, but it evidences the concerns of residents for their ecological safety. Residents of Wola were not allowed to participate in a fair planning process in terms of environmental justice. Aspects of environmental justice, such as equal distribution of activities, land use, nature conservation, and safety of residents, as well as promotion of compatible land uses, were omitted in Wola. In conclusion, the lack of local plans in post-industrial areas and unreliable data in the registers of historical land surface pollution are the main reasons influencing the lack of ensuring environmental justice in post-industrial areas, an example of which is the Wola district.